Cancer is defined by uncontrolled growth and the ability to spread.

“well if you look at the broadest properties there are two properties that separate cancer from other cells in the body the first is uncontrolled growth virtually all of the tissues we have fingernails or eyebrows or you name it they'll grow to a given amount and then they'll stop well cancers don't have that signal to stop they'll keep growing and a second is it's the only cell that can arise in one part of the body and spread and live and divide and grow in another part of the body and that's not true of virtually any other kind of kind of cells”