Sickle cell trait keeps Ryan Clark out of Denver playoff game
Scouting the Steelers: Key Schematic Elements and Matchups in Patriots- Steelers
A carrier of the sickle cell anemia trait, Ryan Clark has made finding a cure for the disease a top priority
Stephen Boyle: Paralyzed Luther College player Chris Norton inspiring with recovery - Sports Illustrated
Ryan Clark (American football) - Wikipedia
NCAA Division I American football players with sickle cell trait have altered hematological responses and hydration status
Sickle Cell Trait Forces Steelers to Bench Player for Playoff Game in Denver
Super Bowl-winning NFL player Ronnie Hillman dies from rare form of cancer at 31
Free Care Fund: UPMC Children's Hospital staff helps Lacqueeta stay positive during challenges of sickle cell disease - CBS Pittsburgh
The Doctor Is In: Is Sickle Cell Trait Too Dangerous In Denver? - Steelers Depot
Steelers Done In by Their Pass Defense - The New York Times
Opinion Damar Hamlin Injury Tested Our Commitment to What Matters. The NFL Failed
How high-risk NFL players arrived at their choices, and what's next - Sports Illustrated
Former Steelers Safety Ryan Clark Provides Sensational Perspective During Horrific Week 17 MNF Incident