DENVER (KDVR) — Former running back Ronnie Hillman, who helped the Denver Broncos win the 2015 Super Bowl, has died, according to his family. He was 31.

Hillman’s family shared the news on his Instagram account, explaining that the former Broncos player had been diagnosed with Renal Medullary Carcinoma in August.

“RMC is a rare but highly aggressive neoplasm form of cancer that primarily affects young African Americans with sickle cell trait,” his family wrote on Instagram.

On Wednesday, Hillman’s family said his treatment had not been successful and he quietly passed away.

Hillman’s family left this message on his Instagram accompanied by a photo of the beloved running back smiling in his Broncos jersey:

It is with heavy hearts that we announce the passing of our beloved son, brother and father, Ronnie K. Hillman Jr. 

Ronnie quietly and peacefully transitioned today in the company of his family and close friends. 

We as the family, appreciate the prayers and kind words that have already been expressed. We ask that you would give us time to process our feelings as we prepare to lay our precious RJ to rest.  

More information will be forthcoming.

With love, The Family

The Broncos, too, released a statement on Hillman’s passing Thursday morning.

“We are deeply saddened by the untimely passing of former Denver Broncos running back Ronnie Hillman,” reads a message posted to the team’s official social media channels. “A key contributor to the winningest four-year period in franchise history, Ronnie was part of two Super Bowl teams and led the Broncos in rushing during our Super Bowl 50 championship season. Soft-spoken with a warm smile and quiet intensity, Ronnie was drafted by the Broncos in 2012 and grew into a dynamic player and well-respected teammate. He will be fondly remembered by our organization, which extends its heartfelt sympathies and condolences to the Hillman family during this difficult time.”

Hillman was a third-round pick from San Diego State in 2012. He spent four seasons with the boys in orange and blue before spending his 2016 season with the Minnesota Vikings and the then-San Diego Chargers.