COMP and psoriasis: The contribution of certain HLA‐B and HLA‐C alleles to the susceptibility to PsA among patients with psoriasis was analyzed in another study [73], while the biomarkers metalloproteinase (MMP)-3 and cartilage oligomeric matrix protein (COMP) were found to be predictive of drug responses to anti-TNF therapy in patients with PsA [74].