ISTANBUL — The grieving refugee who touched hearts as “The Scientist” on the Humans of New York blog only mustered a brief smile when told that a Hollywood star had helped raise $450,000 for him.

Hours before flying to Michigan to start a new life in the U.S. on Thursday, the cancer-stricken Syrian civil engineer glanced down.

"I didn't hear about it, but I want to thank him very much from the humanity perspective," he said after NBC News revealed the crowdfunding appeal. Oscar-nominated actor Edward Norton was moved to tears after reading the refugee's biography on the photography site last week and launched the fundraiser.

"There are people outside who need that money much more than me," The Scientist said, displaying the sort of compassion and humility that helped his story go viral.

The Scientist, who asked NBC News to refer to him as "Abu Ammar" to protect family in Syria, said his life was shattered by a bomb that killed his wife and daughter just under three years ago.

He was later diagnosed with stomach cancer, and has had to care for five remaining children.

They include a teenage son, who is still reeling after watching his mother die, and a daughter who carries inside of her shrapnel from the attack on April 6, 2013.

"When a bomb drops you don't know where it comes from," he said. "There is no question our lives changed after that ... 180 degrees. I am mentally tired, in overwhelming sadness."

"As long as there are good people in the world ... then we can stop this bloodshed"

On Thursday, Abu Ammar and four of his children flew to Troy, Michigan, as part of a United Nations refugee resettlement program.

For about two years, the family had been living close to destitution in Turkey. But the drive to succeed still lingers, Abu Ammar said.

"I've had ambitions since I was a child, and right now I'm still that same child with the same ambitions," he said. "But I still have a message — sometimes when I'm talking to myself I say, 'No, I'm not supposed to die. I need to live long enough to realize my message to humanity.'"

Abu Ammar's story on Humans of New York, a popular blog started in 2010 that spawned a bestselling book, prompted an outpouring of compassion. Even President Barack Obama contributed, calling Abu Ammar and his family an "inspirations" on HONY's Facebook page.

"Yes, you can still make a difference in the world, and we're proud that you'll pursue your dreams here." Obama wrote. "Welcome to your new home. You're part of what makes America great."

Last night President @BarackObama wrote a very sweet welcome note to the scientist in Tuesday's story. pic.twitter.com/ZGrn3gOdR7 — Brandon Stanton (@humansofny) December 10, 2015

Norton, who starred in "Birdman," "Fight Club" and "American History X," set out to help pay The Scientist's medical expenses.

"This man has suffered profound loss that would crush the spirit of many people and yet he still passionately wants a chance to contribute positively to the world," Norton wrote.

The resettlement of Syrian and Muslim refugees in the United States is controversial, especially in the aftermath of attacks by Islamic extremists in Paris and San Bernardino. Some politicians — notably GOP presidential hopeful Donald Trump — have called for a ban on Muslims entering the country.

Abu Ammar told NBC News he didn't know anything about the debate over Muslims and immigration raging in the U.S. He also didn't have a solution to the war raging in his home country.

"I don't like to get into politics because I am a man of science, and I can separate science and politics completely," he said. "But as long as there are good people in the world, and everyone looks into his or her conscience, then we can stop this bloodshed."

Abu Ammar added: "No one benefits from people dying, and wars overall never benefit anybody — so let's hope God can help everyone and put out this fire."