IL6 and rheumatoid arthritis: In the serum of RA patients, HC-gp39 was positively correlated with interleukin-6 (IL-6) and C-reactive protein (CRP), and it can regulate vascular endothelial growth factor, which plays an important role in inflammation, angiogenesis, cell proliferation and differentiation, extracellular matrix remodeling, and anti-apoptosis (22).