TV and movie star Michael J. Fox, 59, is reflecting on his life with Parkinson's disease in a new memoir.
Reflecting in the book on his own mortality, Fox said he's entering a second retirement from acting while also noting that mindset could change.
Known as the time-traveler Marty McFly in the "Back to the Future" series and Republican teenager Alex P. Keaton in "Family Ties," among other roles, Fox continued to work in the industry as he faced the effects of Parkinson's.
The brain disorder can cause mobility issues and usually affects people around age 60 and older. Some people develop an early onset form of the disease before age 50.
Fox was diagnosed with the disease at age 29 in 1991 but didn't reveal it publicly until 1998. In 2000, he announced he was leaving his role on the sitcom "Spin City" because of the weekly toll.
That year, he also founded a Parkinson's foundation, which seeks to find a cure for the disease by funding research and seeking to develop improved therapies for those with it.