Michael J. Fox says he was "stunned" to discover that his friend, supporter, and former prime-time rival Robin Williams also suffered from Parkinson's Disease. "Stunned to learn Robin had PD. Pretty sure his support for our Fdn predated his diagnosis. A true friend; I wish him peace," Fox tweeted, referring to Williams' fundraising for the Michael J. Fox Foundation for Parkinson’s Research, the Independent reports. Williams was in the early stages of the disease, his wife revealed yesterday. Fox, who described Williams as "famously kind, ferociously funny, a genius, and a gentle soul," was diagnosed with the disease in 1991, but did not make the diagnosis public until seven years later, ABC notes.