Ryan Reynolds is mourning the loss of his father and has paid tribute to him on Twitter.
"RIP Pops. James C. Reynolds. 1941-2015," the "Deadpool" actor tweeted, sharing a baby picture of himself being carried by his dad and urging followers to support the Michael J. Fox Foundation for Parkinson's Research.
James Chester Reynolds died Oct. 25 after battling Parkinson's disease, according to his online obituary. He was 74.
The obituary said family and friends were by his side when he "passed away peacefully" in a White Rock, British Columbia, Canada, hospital.
The elder Reynolds is survived by his wife, Tammy, and four sons who "he was intensely proud of," a sister, a brother and six grandchildren, all of whom were mentioned by name, including Ryan Reynolds and Blake Lively's daughter, James.
"Despite health challenges that could have slowed him down, Jim was a strong and passionate man who lived life to the fullest. His spirit, stories and memories live on in his sons and grandkids," the piece said.
No formal service is being held and, in lieu of flowers, the family suggested donations to the Michael J. Fox Foundation as well.
The 39-year-old actor opened up about his father's illness in a 2008 essay for the Huffington Post titled "Why I'm Running the New York City Marathon." Reynolds ran the marathon on behalf of the foundation.
"While I'll probably never fully understand Michael's struggle, I've had a firsthand peek behind the curtain of Parkinson's," the action star wrote. "I've watched my father -- a strong and proud person who successfully raised 4 arguably insane children -- slowly, cruelly stripped of his independence. His golden years robbed without explanation. It quite obviously sucks. Witnessing my Dad suffer over the years galvanized my need to step up."
Jim Reynolds never publicly revealed that he had the disease and his son said that it wasn't officially diagnosed until 1995.
"I have a slightly different, weird, strange story about that because my father really hasn't ever said he has Parkinson's disease," Reynolds said in a November 2014 interview on the "Today" show. "He's in his 70s. He comes from a pretty prideful generation, and he doesn't really talk about it too much. But, he's maybe said it once or twice out loud."
The actor teamed up with "Back to the Future" alum Fox in 2008 and has served as a board member for the foundation. Parkinson's is a chronic, degenerative neurological disorder that affects one in 100 people over the age of 60, according to the foundation.
"It kind of galvanized everybody else, to sort of seek resources," Reynolds said. "And for us, it's in a strange way, it's really kind of brought us together."