(NewsNation) — Actor Gary Sinise, the “Forrest Gump” co-star and veterans advocate, has only recently begun talking about losing his musician son to a rare form of cancer last year but has some positives to share following the tragedy.

Mac Sinise was only 33 when he died of chordoma in January 2024. The younger Sinise had been diagnosed with the rare type of bone cancer in 2018, the same year Gary Sinise’s wife, Moira, was diagnosed with Stage 3 breast cancer. The dual medical crises necessitated the actor’s exit from Hollywood, he said.

“It was just a full-time job to manage the medical needs that they were both going through,” Gary Sinise told “NewsNation Prime” on Sunday.

Gary Sinise’s son finished record before his death

While his wife went into remission, he said Mac is among the roughly 30% of chordoma patients who don’t make it. In early 2023, Mac Sinise decided he wanted to finish a composition that he had begun in college. He died weeks after recording the material, which Gary Sinise says has gained traction on iTunes in addition to being performed publicly.

“I just saw Mac persevere through all of this in the most humble, graceful, inspirational way,” the father said. “Telling his story, talking about him and sharing the music with people is a wonderful gift that I have. While we never got the medical miracle that we were looking for, there were many other miracles that we did receive.”

The 70-year-old Sinise starred in the CBS police procedural “CSI: NY” from 2004 to 2013 but is probably best remembered for playing Lt. Dan Taylor in 1994’s “Forrest Gump,” for which he was Oscar-nominated. That role is also the namesake of his philanthropic cover band, which performs on behalf of U.S. service members and veterans through his Gary Sinise Foundation.

Grieve, yes, but power forward, Gary Sinise says

Sinise said his experience losing his son has taught him life shouldn’t stop at the loss of a loved one — something he witnessed working with bereaved military families.

“Going through grief is part of the human experience, and we have to be thankful for the time that we have with the loved ones that we have and just persevere in their honor,” he said. “Move on and forge ahead in their honor and memory.”