New York (CNN Business) Paul Allen, the billionaire co-founder of Microsoft, died Monday. He was an investor, entrepreneur and philanthropist who influenced many aspects of modern life — from technology and science to sports and music.

Allen was 65, his investment firm Vulcan said in a statement announcing his death. He died in Seattle from complications related to non-Hodgkin's lymphoma two weeks after Allen said he was being treated for the disease.

Non-Hodgkin's lymphoma, like the less-common Hodgkin's disease, is a cancer of the lymphatic system.

"My brother was a remarkable individual on every level," Allen's sister, Jody Allen, said in a statement on behalf of his family. "He was a much loved brother and uncle, and an exceptional friend."

Allen founded Microsoft ( MSFT ) with Bill Gates in 1975, several years after the two met as fellow students at a private school in Seattle. Allen left the company in 1982 after he was diagnosed with Hodgkin's disease.

Seattle Seahawks owner Paul Allen and head coach Pete Carroll of the Seattle Seahawks celebrate after the Seahawks defeated the Green Bay Packers in the 2015 NFC Championship game at Century Link Field on January 18, 2015 in Seattle, Washington.

Seattle Seahawks owner Paul Allen and head coach Pete Carroll of the Seattle Seahawks celebrate after the Seahawks defeated the Green Bay Packers in the 2015 NFC Championship game at Century Link Field on January 18, 2015 in Seattle, Washington.

President Barack Obama congratulates Seattle Seahawks owner Paul Allen during a ceremony honoring the players, coaches and executives of the Super Bowl XLVIII champions in the East Room of the White House May 21, 2014 in Washington, DC.

President Barack Obama congratulates Seattle Seahawks owner Paul Allen during a ceremony honoring the players, coaches and executives of the Super Bowl XLVIII champions in the East Room of the White House May 21, 2014 in Washington, DC.

Team Owner Paul Allen of the Seattle Seahawks holds the Lombardi Trophy during ceremonies following the Super Bowl XLVIII Victory Parade at Century Link Field on February 5, 2014, in Seattle, Washington.

Team Owner Paul Allen of the Seattle Seahawks holds the Lombardi Trophy during ceremonies following the Super Bowl XLVIII Victory Parade at Century Link Field on February 5, 2014, in Seattle, Washington.

Paul Allen, owner of the Portland Trail Blazers, center, sits with team president Larry Miller, left, and Pete Carroll, head coach of the National Football League's Seattle Seahawks, during a Blazers game against the Utah Jazz on April 18, 2012, at the Rose Garden Arena in Portland, Oregon.

Paul Allen, owner of the Portland Trail Blazers, center, sits with team president Larry Miller, left, and Pete Carroll, head coach of the National Football League's Seattle Seahawks, during a Blazers game against the Utah Jazz on April 18, 2012, at the Rose Garden Arena in Portland, Oregon.

Seahawks owner Paul Allen holds up the NFC Championship trophy following his team's victory over the Carolina Panthers at Qwest Stadium on January 22, 2006.

Seahawks owner Paul Allen holds up the NFC Championship trophy following his team's victory over the Carolina Panthers at Qwest Stadium on January 22, 2006.

Portland Trail Blazers owner Paul Allen arrives at a press conference with the team's new head coach, Nate McMillan, left, and team president Steve Patterson, right, on July 7, 2005 at Washington Park in Portland, Oregon.

Portland Trail Blazers owner Paul Allen arrives at a press conference with the team's new head coach, Nate McMillan, left, and team president Steve Patterson, right, on July 7, 2005 at Washington Park in Portland, Oregon.

Stuart Varney of Fox News, left, moderates a panel featuring Paul Allen, Time Warner CEO Richard Parsons, and Comcast CEO Brian Roberts in New Orleans, Louisiana on May 3, 2004.

Stuart Varney of Fox News, left, moderates a panel featuring Paul Allen, Time Warner CEO Richard Parsons, and Comcast CEO Brian Roberts in New Orleans, Louisiana on May 3, 2004.

Paul Allen, left, talks with Jeffrey Katzenberg of DreamWorks outside the Inn in the Sun Valley resort during the Allen & Co conference in Sun Valley, Idaho on July 9, 2004.

Paul Allen, left, talks with Jeffrey Katzenberg of DreamWorks outside the Inn in the Sun Valley resort during the Allen & Co conference in Sun Valley, Idaho on July 9, 2004.

Allen sits courtside with Portland Trail Blazers President Bob Whitsitt, left, during the Round One Playoff Game 3 against the Los Angeles Lakers at the Rose Garden in Portland, Oregon in 2001. Allen bought two professional sports teams -- the NBA's Trail Blazers and the NFL's Seattle Seahawks -- and was involved with both until his death.

Allen sits courtside with Portland Trail Blazers President Bob Whitsitt, left, during the Round One Playoff Game 3 against the Los Angeles Lakers at the Rose Garden in Portland, Oregon in 2001. Allen bought two professional sports teams -- the NBA's Trail Blazers and the NFL's Seattle Seahawks -- and was involved with both until his death.

In his later years, Paul Allen took up a number of other projects -- from the charitable to the adventurous. On June 23, 2000, he christened his Experience Music Project museum by smashing a replica Stratocaster guitar at the grand opening in Seattle, Washington.

In his later years, Paul Allen took up a number of other projects -- from the charitable to the adventurous. On June 23, 2000, he christened his Experience Music Project museum by smashing a replica Stratocaster guitar at the grand opening in Seattle, Washington.

Microsoft co-founders Bill Gates, center, and Paul Allen, left, watch the third game of the Western Conference Finals between the Los Angeles Lakers and the Portland Trail Blazers in Portland, Oregon on May 26, 2000.

Microsoft co-founders Bill Gates, center, and Paul Allen, left, watch the third game of the Western Conference Finals between the Los Angeles Lakers and the Portland Trail Blazers in Portland, Oregon on May 26, 2000.

Paul Allen plays acoustic guitar at the annual PC Forum in Tucson, Arizona, in March 1991, accompanied on the piano by Jerrold Kaplan of GO Corporation/Egghead.

Paul Allen plays acoustic guitar at the annual PC Forum in Tucson, Arizona, in March 1991, accompanied on the piano by Jerrold Kaplan of GO Corporation/Egghead.

Tech journalist John Dvorak, left, with Paul Allen, center, and Esther Dyson from EDventure Holdings, right, at the annual PC Forum in Palm Springs, California in March 1989.

Tech journalist John Dvorak, left, with Paul Allen, center, and Esther Dyson from EDventure Holdings, right, at the annual PC Forum in Palm Springs, California in March 1989.

Paul Allen, left, with Bill Gates at the annual PC Forum in Phoenix, Arizona in February 1987. "I am heartbroken by the passing of one of my oldest and dearest friends, Paul Allen," Gates said in a statement Monday.

Paul Allen, left, with Bill Gates at the annual PC Forum in Phoenix, Arizona in February 1987. "I am heartbroken by the passing of one of my oldest and dearest friends, Paul Allen," Gates said in a statement Monday.

Paul Allen with Bill Gates. The two founded Microsoft in 1975, several years after the they met as students at a private school in Seattle.

Paul Allen with Bill Gates. The two founded Microsoft in 1975, several years after the they met as students at a private school in Seattle.

Paul Allen, philanthropist and co-founder of Microsoft, died on October 15, 2018, at age 65. He died in Seattle from complications related to non-Hodgkin's lymphoma two weeks after he said he was being treated for the disease.

Paul Allen, philanthropist and co-founder of Microsoft, died on October 15, 2018, at age 65. He died in Seattle from complications related to non-Hodgkin's lymphoma two weeks after he said he was being treated for the disease.

"I am heartbroken by the passing of one of my oldest and dearest friends, Paul Allen," Microsoft founder Bill Gates said in a statement Monday. "Paul was a true partner and dear friend. Personal computing would not have existed without him."

"As co-founder of Microsoft, in his own quiet and persistent way, he created magical products, experiences and institutions, and in doing so, he changed the world," Nadella added.

Allen didn't slow down after leaving Microsoft. He stayed on the company's board of directors for several years while establishing his own philanthropic foundation, along with Vulcan, his investment firm.

Paul Allen in New York, Oct. 15, 2015. Joshua Bright/The New York Times

He bought two professional sports teams: the NBA's Portland Trail Blazers and the NFL's Seattle Seahawks. He was involved with both until his death.

"Paul Allen was the ultimate trail blazer," NBA Commissioner Adam Silver said in a statement, adding that Allen was one of the league's longest-tenured owners. "He was a valued voice who challenged assumptions and conventional wisdom."

NFL Commissioner Roger Goodell called him the "driving force" behind keeping the NFL in the Pacific Northwest. In a statement, Goodell said Allen "worked tirelessly alongside our medical advisers to identify new ways to make the game safer and protect our players from unnecessary risk."

Friends, family and other admirers also praised Allen for his significant philanthropic contributions.

The technologist, who Forbes says was worth $20.3 billion at the time of his death, donated more than $2 billion to charity. He also founded several organizations, including the space transportation company Stratolaunch, the Allen Institute for Artificial Intelligence and another Allen Institute that focuses on bioscience. Vulcan, which he founded, managed his business and philanthropic interests.

So sad to hear about the passing of Paul Allen. Among many other things he was a pioneer of commercial space travel. We shared a belief that by exploring space in new ways we can improve life on Earth. All our thoughts are with his loved ones. — Richard Branson (@richardbranson) October 15, 2018

"We shared a belief that by exploring space in new ways we can improve life on Earth," said Virgin Group founder and CEO Richard Branson.

"All of us who had the honor of working with Paul feel inexpressible loss today." said Vulcan CEO Bill Hilf. "Today we mourn our boss, mentor and friend whose 65 years were too short — and acknowledge the honor it has been to work alongside someone whose life transformed the world."

Actor Leonardo DiCaprio, who worked with Allen on shark conservation, shared his condolences via Twitter

"Sad to hear of the passing of Paul Allen, who was a strong advocate for environmental protection," DiCaprio said. "His legacy lives on via his incredible work as a philanthropist and investor."

Allen was also known for his love of music. In a 2013 interview with Guitar Player , Allen recalled how listening to "Are You Experienced" by the Jimi Hendrix Experience prompted him to start playing guitar.

"That was a life-changing moment," he told the publication. "I think I was 14 when I heard it. That was just music from another planet."

In 1995, Allen even loaned money to Hendrix's family during a legal battle to regain rights to the guitarist's image and music, The Washington Post reported . He also funded a $100 million museum for music and pop culture in Seattle, now called the Museum of Pop Culture.

Musician and music producer Quincy Jones mourned Allen's death Monday evening, called him a "dear friend" and "killer guitar player."

In his later years, Paul Allen took up a number of other projects -— from the charitable to the adventurous.

Allen was still finding other ways to leave his mark on the world this year. A team of explorers led by him discovered wreckage in March from the USS Juneau, a World War II cruiser sunk by a Japanese torpedo in 1942.

His efforts to build the world's largest plane were also recently profiled by Paul Levy, an editor at large at Wired Magazine. Speaking at the WIRED25 conference in San Francisco on Monday, Levy praised Allen's accomplishments and said he would leave a mark.

"He and his partner Bill Gates [were] instrumental in pushing the needle and helping make all the things happen that we're talking about today," Levy said. "His imprint will be on all of us."

RIP Paul. You were a good man and will be missed. Rock and Roll Heaven just got a lot better https://t.co/bOSmF5Dcqi — Mark Cuban (@mcuban) October 15, 2018

Mark Cuban, the billionaire entrepreneur and owner of the Dallas Mavericks, also tweeted his condolences.

"You were a good man and will be missed," Cuban said. "Rock and Roll Heaven just got a lot better."