. >> nike's cofounder phil knight is offering half a billion for cancer research. there's a big catch. he wants others to match his offer in two years. the money could go to oregon's health and science university, knight gave the school $100 million to fund a cancer center with his name. there'll be no consolation prize if the university does not raise the other $500,000. >> an unlikely friendship is growing at the dallas zoo. two cheetah cubs and a puppy are proving that cat and dog can get along. >> welcome to the dallas zoo wild encounter stage. for those of you that don't know, cheetahs are found in africa. >> the trio is the toast of the dallas zoo. twin brothers are 2.5-year-old chooetas. they meat aman ni three weeks ago. the pairing comes at the behest of officials. >> we don't know if the chooetas think he's a cheetah, or the dog thinks they are dogs. >> it's been playdates. the three will eventually spend their time together. >> >> chris johnson says it taps into the cheetah's companionship. >> brothers stay together. we are mimicking that with the dog. w