On April 8, Mark Gastineau emerged from his eighth and final chemotherapy session and walked through the first-floor waiting room at the Fox Chase Cancer Center in Philadelphia. Wiping tears from his eyes, he stopped at an antique ship bell mounted on the wall beneath a flat-screen TV. Eschewing the nearby box of tissues, he reached for the bell. Old No. 99, wearing an NFL alumni shirt underneath an unbuttoned, blue-denim, long-sleeved shirt, turned this into a vintage Gastineau moment.

The former New York Jets star rang the bell as part of Fox Chase's traditional, end-of-chemo ceremony. Five nurses, a couple of receptionists and a handful of patients came out to watch Gastineau, once a flamboyant sack dancer, perform before the assembling crowd.

Former Jets defensive end Mark Gastineau celebrates the end of his chemotherapy treatments for colon cancer with his wife, Jo Ann, on April 8. Courtesy of Mark Gastineau

Battling the sinister effects of chemo, Gastineau kept ringing the bell, louder and louder, shimmying his 6-foot-5 frame as if he had just recorded his 75th quarterback sack after a three-decade hiatus. He rang it with such gusto that screws loosened from the wall. There were hugs and more tears, leaving wet spots on his shirt. He posed for pictures with his wife, Jo Ann. Together, they held a big sign that said, "I SURVIVED CHEMO!"

"Oh, man, it was so good. It was so good," Gastineau said two weeks later. "Even though I was so sick, it was still so joyous."

"I tell you what, he rang that bell better than a sack dance," Jo Ann said, laughing. "[We're] sacking cancer all the way. The Lord has been protecting us and taking care of us."

Gastineau, one the NFL's most feared pass-rushers in the 1980s, was diagnosed last October with stage 3 colon cancer. A year earlier, doctors told him that a brain scan had revealed the onset of dementia. Once upon a time, he was a larger-than-life celebrity athlete who drove a Rolls-Royce, wore a mink coat and partied at the trendiest clubs in Manhattan. Now 62, his mind and body are betraying him. His medical bills are so high that he's on the verge of losing his home in Yardville, New Jersey, where he has lived since 2003.

Life has turned on Gastineau, but he tries to remain upbeat. "Alive is me," he tells people. He has been in the spotlight for 40 years, not all of it pleasant, but he appreciates the journey more than ever. It all started with an out-of-the-blue phone call from a woman in Long Island, New York.

On May 3, 1979, the Jets drafted Gastineau in the second round, 41st overall. This was the year before ESPN televised its first draft, before Mel Kiper Jr. was a household name and before every top prospect attended the draft with his entourage. In Gastineau's day, there was no fanfare. The player waited in his home, hoping the phone would ring with life-changing news. It was an era when it was possible to discover a true draft sleeper.

That described Gastineau, a no-name defensive end out of East Central Oklahoma. He became one of the best draft picks in team history, a five-time Pro Bowler, a three-time All-Pro and a member of the Jets' Ring of Honor. Aside from Joe Namath, he might be the franchise's most popular player, still a fan magnet after all these years. Owner Woody Johnson once told Gastineau's wife that Mark and the New York Sack Exchange -- the four-man front that terrorized quarterbacks in the early 1980s -- were critical to the growth of the franchise.

If it weren't for Connie Nicholas Carberg, a scouting assistant, Gastineau never would've made it to Gotham.

"The biggest thrill, I think, was getting that phone call from Connie," Gastineau said. "That was definitely the biggest thrill of my life. I can remember her voice right now."

The Jets' staff, assigned to coach the Senior Bowl in Mobile, Alabama, asked Nicholas Carberg to find a last-minute replacement player for an Iowa State defensive lineman named Mike Stensrud, who was injured in a snowmobile accident. Nicholas Carberg, known around the Jets' offices as "The Girl Scout," pulled film and scouting reports of a few candidates. One of them stood out because of his speed. She decided to call them individually to conduct quasi job interviews.

Most sacks in single season Year NFL Player Sacks 2001 Michael Strahan 22.5 2014 Justin Houston 22.0 2011 Jared Allen 22.0 1984 Mark Gastineau 22.0 Source: ESPN Stats & Info

She was blown away by Gastineau's passion on the phone, so she extended the 11th-hour invite to him. He was at his brother-in-law's restaurant Safire in Arizona's White Mountains when he got the call.

"He said, 'I'm ready, just get me on the next plane. This is a dream come true, just get me there. I'm ready to play football,'" she recalled. "You could hear the enthusiasm. I looked, and it turned out to be the one with the speed. It turned out to be Mark."

For Gastineau, who grew up in dusty towns in Arizona and Oklahoma, it was a game-changer. When he arrived in Mobile, he saw a marquee in town with his name in flashing lights.

Welcome, Mark Gastineau.

"Just for a second," he said, "it was the most exciting thing in the world."

Once he got on the field, Gastineau impressed the scouts and was named the top lineman on the North Squad. He was clocked under 4.6 seconds in the 40-yard dash, a ridiculous time for a 260-pound man. If there had been social media, he would have blown up Twitter. The Jets were concerned because their little secret from East Central Oklahoma was starting to become known in the scouting community, and they nearly lost him to the Buffalo Bills.

With the fourth pick in the second round, 32 overall, the Bills called Gastineau to let him know their plans to select him -- except they didn't. They made a mistake and called him back, apologizing for their error. They wound up picking nose tackle Fred Smerlas, who enjoyed a long NFL career. Nine picks later, the Jets called with the news -- and theirs wasn't fake. It was Nicholas Carberg, naturally thrilled with the choice, who phoned in the pick to draft headquarters in New York. She and Gastineau would become lifelong friends.

Gastineau, at his parents' 220-acre ranch in Ravia, Oklahoma (current population: 525), was so excited that he pounded his fist into a 100-year-old oak table -- and split the wood. What a journey. As a kid, he broke a leg so severely in a backyard accident that doctors weren't sure whether he would walk again. When he transferred from Arizona State, his coach -- the maniacal Frank Kush -- told him he would never make it in the NFL. Now he was headed to the league and to New York City.

"They said the roof of my mouth got sunburn from gawking at the skyscrapers," Gastineau said, laughing.

Gastineau became the quintessential speed rusher, peaking in 1984 with a then-record 22 sacks in a season. He was one of the most polarizing players in the league because his celebratory sack dances, which were eventually outlawed, infuriated opponents. One time it sparked a vicious fight with future Pro Football Hall of Famer Jackie Slater. At the time, Gastineau seemed unfazed by the criticism. After all, he was one of the biggest names in the sport. He was a Sports Illustrated cover boy. He was a paparazzi favorite. He was a rock star who performed every Sunday.

Truth is, it did hurt.

"I got a lot of s-s-s-s-sacks -- and I got a lot of punishment for it," he said, his voice rising and falling in the same sentence. "That's OK. I'm not going to say I paved the road, but you know what? I had a lot of fun doing it. I can't say I felt bad about getting sacks. It could've been a lot better if I didn't have all the negative publicity, but you know what? Looking back on it, my career, I had a lot of ups and downs. There's been a lot of negative publicity on me. The things that are negative, I try to block out.

"We can't focus on the negative. The past has no future."

He would be making $20 million a year if he were playing today. Some might say he redefined his position.

"I don't think a lot of people think that," he said.

He was the sack king before sacks became an official statistic in 1982. He held the single-season record until Michael Strahan broke it in 2001 with 22.5.

"If people know about it, they'll come up to me every once in a while and say, 'You were a really great player,' and I appreciate that," Gastineau said. "But I'm not going around making quotes about how good I was. I'm just going around being Mark Gastineau and trying to get through this cancer I'm going through."

A member of the Jets' celebrated "New York Sack Exchange" line, Mark Gastineau was one of the league's biggest stars in the 1980s. He retired abruptly in 1988 and became a professional boxer. George Gojkovich/Getty Images

When Gastineau went for a colonoscopy last October, his doctors knew immediately that something was wrong. They detected a malignancy so clearly that they told Mark and Jo Ann on the spot before the biopsy results. The tumor was removed at Fox Chase, where he spent three weeks recovering from surgery.

A game plan was set: Eight chemotherapy sessions, followed by 5½ weeks of radiation, five times a week. He's in the middle of the radiation phase, optimistic he will beat the cancer, but knows it's only "halftime" in this battle.

"There's no way to describe it," Gastineau said of the disease. "It's tough to describe, but you know what? There's going to be a day when it's over. There are people there that are worse than I am."

Gastineau, who once relished the spotlight, doesn't do a lot of interviews. He agreed to speak to ESPN in part because he wants to raise awareness for colon cancer.

"I think the reason I have this is to tell people to get tested," he said, making this reporter promise he would have a colonoscopy. "[The cancer] came on like a thief in the night."

He relies on his faith more than ever. He belongs to the Times Square Church, an hour's drive from his New Jersey home, and considers pastor Carter Conlon his life preserver. In the middle of his interview with ESPN, Gastineau started praying aloud, asking the Lord to allow this story to touch many people. Friends say this is a different Gastineau than the "look at me" football star who chafed teammates and once invited reporters into his training-camp dorm room to watch him lift weights.

"Mark realizes -- like all of us -- that we're closer to the end than the beginning," said former teammate Marty Lyons, who teamed with Gastineau, Joe Klecko and Abdul Salaam to comprise the celebrated Sack Exchange. "He's been humbled and he's thankful. Maybe he didn't say 'thank you' to enough people along the way, but it's not too late. He has a long battle in front of him, but the one thing he has now that he didn't have before is his faith."

When Lyons heard about the cancer, he called Gastineau to offer support. His former teammate is hurting physically and financially, so Lyons organized a fundraiser. Old bonds don't break, no matter the length of the friendship.

In the 1980s, Gastineau was one of the highest-paid defensive players in the NFL, averaging close to $800,000 per year. In 1991, three years after he retired abruptly in the middle of the season, he lost all his assets in a stormy divorce with his first wife, the Associated Press reported at the time. Medical costs have mounted in recent years, prompting the Gastineaus to create a GoFundMe page at the behest of their pastor. In 2017, Gastineau announced he had been diagnosed with dementia, Alzheimer's disease and Parkinson's disease. A year later, he did a radio interview in which he delivered a plea to NFL commissioner Roger Goodell, asking the league to help ailing players.

"It's been tough," Jo Ann said. "This is a really, really tough time."

Despite the adversity, Gastineau maintains an endearing, boyish charm. In some ways, he's still the same No. 99 who danced over his prey on the football field. After chemo treatments, he walked around the facility, visiting other patients and giving pep talks. He turned the cancer ward into a football sideline, trying to fire up his new teammates. He chanted:

Fox Chase is No. 1! Fox Chase is the best! Let's go, let's go!

"They looked at me like I was crazy," he said. "But, all of a sudden, they said, 'Yeah! Yeah!'"

Gastineau, once famous for knocking people down, now picks them up. And he could use a little of that himself.