Gary Sinise, who played Forrest Gump and CSI: NY, and his son MAC Sinise have both died.

MAC Sinise was 33 years old and had been sick with a rare cancer.

Gary shared the sad news on Tuesday in a post on the website for the Gary Sinise Foundation.

He told everyone that his son died on January 5 after a long battle with Chordoma, a rare form of spinal cancer.

Mac, whose real name was McCanna Anthony, played drums for his father’s Lt. Dan Band and worked with the Gary Sinise Foundation until he had to stop because his cancer was getting worse and he needed more surgeries on his back.

In the moving tribute, Gary talked about the two terrible things that happened to his family in the summer of 2018. Moira, Gary’s wife, was diagnosed with stage 3 breast cancer in June, just two months before Mac was diagnosed with chordoma in August of that same year.

After surgery to remove lymph nodes and chemotherapy and radiation treatments, Moira’s cancer went into remission, which was a relief.

Mac, on the other hand, was sadly killed by the disease.

Gary said this about Mac’s work for the foundation: “Mac joined the team at the Gary Sinise Foundation as our Assistant Manager of Education and Outreach.”

“I was thrilled and excited to have him come on board to help me with the mission.”

“I was always happy to have him join me on the road, and I could see how much joy and pride he shared in our mission,” he said.

“Especially when he could be hands-on with those we serve, like at our Soaring Valor events honoring our nation’s WWII heroes, and our Invincible Spirit Festivals, where we bring the Lt. Dan Band to uplift our wounded at military hospitals across the country.”

He talked about how good Mac was as a musician and said that his son had been playing the drums since he was nine years old and “was an exceptional drummer.”

Gary added in a sweet way that playing in the Lt. Dan Band with Mac was “great times” and that they had fun “rockin’ out together for the troops.”

The well-known CSI actor talked about how uncommon Mac’s cancer is. He said that Chordoma is a “one in a million” type of cancer that starts in the sprint and “affects, on average, only 300 people in the U.S. per year.”

Gary talked about how Mac was still eager to help the Foundation while he was recovering at home after having several surgeries on his back.

Mac showed his strength when, in January 2020, the day before his fourth surgery on his spine, he joined Gary for a GSF podcast interview, even though he was sick.

As of the interview, Mac’s work with the Gary Sinise Foundation was over. He had to take a break to focus on his recovery and rehab full-time.

Mac was laid to rest on January 23 after his battle with the disease was over.

“Like any family experiencing such a loss, we are heartbroken and have been managing as best we can,” Gary told us.

“Losing a child is so hard for parents.” My heart goes out to everyone who has lost a loved one or been through a similar loss.

“In some way, we’ve all been through it. Over the years, I’ve met a lot of families of our heroes who have died. “It breaks my heart and is just so damn hard,” he said.

“Our hearts hurt because we miss him, but we’re glad Mac is no longer having a hard time. We’re inspired and moved by how he dealt with it.” He had a hard time beating a cancer that has no cure, but he never gave up.

“I am so blessed, fortunate, and proud to be his dad,” he told me.