Facing inoperable cancer, he's encouraging others: 'Don't ever give up'

Mark Grethel has been going non-stop for weeks. He went tubing at Perfect North, traveled to Spring Training in Arizona and visited his daughter in San Francisco. He spent a night on the sidelines with University of Cincinnati's basketball team and on Thursday got a tour of the White House. This is not normal for Mark, but nothing has been normal since late last year. That’s when he was told he has a rare, untreatably form of colon cancer. His doctor estimated he had between six and 12 months left on Earth.