Came across the story via Pro Football Talk:

"Matt Millen, a well-known figure to football fans for his decades as a player, broadcaster and former General Manager of the Lions, is dealing with a rare and serious illness.

Millen told the Morning Call that he is suffering from amyloidosis, a rare illness that has seriously damaged his heart and will likely require him to get a heart transplant."

http://profootballtalk.nbcsports.com/2018/04/28/matt-millen-battling-rar...

I'll admit Millen wasn't easy to follow in Detroit, nor most of his commentary as an analyst, but I respect the man and his principles (his comments in the wake of the PSU tragedy). Wishing him well, and hope to continue to see him on BTN.