TNF and psoriatic arthritis: Tumor necrosis factor α (TNF‐α), a crucial regulator in the immune response, has been the target of multiple approved antibody drugs such as adalimumab, golimumab, and certolizumab.[6] TNF‐α antagonism has shown therapeutic efficacy for several autoimmune diseases such as rheumatoid arthritis (RA),[7] psoriatic arthritis, multiple sclerosis (MS), and Crohn's disease.[8] Nevertheless, only 60–70% of patients achieve a long‐term clinical response.