Ronnie Hillman, a Super Bowl-winning running back for the Denver Broncos, passed away aged 31 on Wednesday, according to a post from his family on his Instagram page.The post from his family reads, “It is with heavy hearts that we announce the passing of our beloved son, brother & father, Ronnie K Hillman Jr.“Ronnie quietly and peacefully transitioned today in the company of his family and close friends.”Renal medullary carcinoma is a highly aggressive cancer that primarily affects people with sickle cell trait (SCT).San Diego State University (SDSU), Hillman’s alma mater, posted a tribute on their football team’s official Twitter.On the school’s website, SDSU’s director of athletics John David Wicker wrote, “We are saddened to hear about the passing of Ronnie Hillman.Ronnie helped resurrect San Diego State football in his two seasons in 2010 and 2011 and has recently been around the program offering wisdom and insight.”SDSU’s head coach Brady Hoke also penned a tribute, saying, “Our deepest condolences go out to Ronnie’s family."