Brain Tumour Forced Ruffalo Out Of Signs
Instead of starring alongside Mel Gibson in the film, Ruffalo took a 10 month break to recover from surgery - with his family.
He says, "It's the most difficult thing I've ever been through, and ended up being one of the most important things that ever happened to me.
"I had been living in this exterior space for so long, and then I was just diving down into myself. I didn't understand what living really is about."