Nobody with any inside knowledge has suggested this, other than GCobb, who seems to be spewing speculation. In a report that he filed on Saturday, Cobb admits that he knows nothing about the illness, and a fan suggests that it might be cancer because you can't get mono twice. But he could still be fighting the symptoms, or it could be something else entirely. Whatever the case, there is no evidence to support that Maclin has cancer, so let's just stop this right now. EDIT: Nothing from GCobb about it either, I misread a comment here. The ONLY person who has stated cancer thus far is a commenter on GCobb's site. Anything about cancer at this point is RAMPANT SPECULATION. Nobody with any inside knowledge has said anything more than illness.