COMP and ankylosing spondylitis: Additional biomarkers of inflammation and cartilage turnover (eg, cartilage oligomeric matrix protein, soluble E‐selectin, and intercellular adhesion molecule‐1) decrease with treatment and have variable predictability of disease response to therapy in other inflammatory skeletal diseases such as juvenile idiopathic arthritis, rheumatoid arthritis, and ankylosing spondylitis.32, 33, 34