IL17F and dermatitis: Other findings also suggested that IL-17F, which is up-regulated in both the skin and synovium of patients with PsA (Sánchez-Rodríguez & Puig, 2023), has been produced by both dermatitis and ankylosing enthesitis and has augmented IL-17A and/or IL-17F signaling through the increase of IL-17RC expression in the enthesis (Figs 1I and 5I).