UFC's Chris Weidman Asking For Support For Nephew Diagnosed With Rare Cancer

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.

The fighter explained the road is going to be a long one -- but he said there are ways people can pitch in and help.

Weidman urged his followers to share his video message, make a donation to Josh's GoFundMe page, and shave their heads to show solidarity with the boy.

In the 38-year-old's video message, Weidman, Josh's brothers, cousins and other family members were all seen cutting off their hair.

The mixed martial artist also shared some of Josh's basketball, football, wrestling and lacrosse highlight clips in his post.

"This is my family," Weidman said. "This is my nephew."

"I just want to be able to help out my family the best way I possibly can. I appreciate your help."