Bengals lineman Devon Still says he and his daughter Leah are devastated by the death of their friend Lauren Hill ... and have vowed to team up with Hill's foundation to continue the fight against cancer.
The Stills got to know Hill while 4-year-old Leah and 19-year-old Lauren were both going through cancer treatments over the past year ... and worked together to raise money for cancer research.
Now, after learning of Lauren's passing ... Devon says he will continue the fight with Lauren's foundation, Club 22 ... which is dedicated to finding a cure for pediatric cancer.
"I will be getting with the family and coaches and definitely furthering awareness and what she's achieved with her foundation. I want to make sure that what she's done and the way she lived is never forgotten."
"We all have to turn all the negative from this into a positive and share what we've learned from Lauren through this tough experience."
And while Hill's death is incredibly sad, Still says it's a "wake up call" about why it's so important to continue to fund cancer research -- "We need to continue to push forward because the outcome of this is real."