Nile Rodgers has been hospitalized with a mystery ailment which forced him to miss a concert on the weekend.

The disco legend and his group Chic is currently on the road with Earth, Wind & Fire for the 2054: The Tour. When the show rolled into the Toronto’s Air Canada Centre on Sunday night (Aug. 13), Rodgers was grounded with illness and taken to hospital where, he says, doctors “are taking great care” of him.

Rodgers is a cancer survivor. The 64-year-old guitarist and producer was diagnosed with prostate cancer six years ago and documented his battle via his blog. In 2014, he was given the all-clear on cancer and he opened up on his ordeal during Chic’s set at Glastonbury Festival in June.

“My doctors told me I was suffering from extremely aggressive cancer and that I needed to go home and get my affairs in order… Well, I happened to get a phone call from two French guys called Daft Punk and a gentleman named Pharrell Williams and we got together and wrote this song called ‘Get Lucky,” he told the crowd. “And I feel like the luckiest man in the world tonight because six years after that doctor told me to go home and get my affairs in order, today, six years later, I am cancer-free!”

Rodgers admits he’s never missed a gig until now. The artist, who accepted the Award for Musical Excellence at April’s Rock and Roll Hall of Fame ceremony, shared a pair of tweets late Sunday to thank his supporters and doctors. At this stage, his condition is unknown and its unclear whether Rodgers will return to the stage for Tuesday night’s show at Bankers Life Fieldhouse in Indianapolis.

Thank you all so much. I love @EarthWindFire @CHICorg all the #fans and my doctors who are taking great care of me. See you all very soon https://t.co/6dl5EFXbza

— Nile Rodgers (@nilerodgers) August 14, 2017

Thanks Johnny. I've never missed one gig in my life… well, it's been that way till now. The Dr. caught me trying to sneak out. #LOVE https://t.co/51S6KBRcKs

— Nile Rodgers (@nilerodgers) August 14, 2017

Nile Rodgers is in hospital tonight. Lights are for him pic.twitter.com/phzwhbs0Uk

— cARL BARNeY (@yablowza) August 14, 2017

This story originally appeared on Billboard.