The 50-year-old actor is one of the most bankable stars in the movie industry, but he doesn't plan to stay in the business forever.
Asked when he plans to leave Hollywood behind, Mark replied: "Sooner rather than later, probably."
Mark has Ella, 18, Michael, 16, Brendan, 13, and Grace, 12, with his wife Rhea Durham, and the actor is keen to spend more time at home with his family in the coming years.
Mark explained: "It's gotta be something special to really bring me, you know, to leave home, to leave those guys behind, because it's the biggest sacrifice in the making for sure."
He told 'Entertainment Tonight': "I feel like this is starting a new chapter for me in that, now, doing things like this - real substance - can help people.