IL4 and Arthritis: Treatment of OA chondrocytes with cytokines (IL-1β, TNF-α, IFN-γ, IL-10, and IL-4) and growth factors (TGF-β, BMP-2, and EGF) involved in arthritis pathophysiology showed that IGFBP-5 expression was increased by all the cytokines tested with statistical significance reached for TNF-α (p < 0.02), IFN-γ (p < 0.0003), and IL-10 (p < 0.01).