UFC star Chris Weidman just shared some awful news ... his nephew was diagnosed with a rare and aggressive form of cancer -- and he's now asking everyone for their help and support.
The former middleweight champ published a video message on his Instagram page on Thursday revealing that his nephew, Josh, was diagnosed with alveolar rhabdomyosarcoma in July. He said it's an extremely rare disease that "starts in the muscle tissue and usually affects athletic young kids."
Weidman said Josh will now have to undergo chemo for 42 weeks in order to try to fight it off.