Other family members, notably IL-17E and IL-17C, are also upregulated in psoriatic skin [143]; IL-17E, produced by both immune cells and KCs, drives KCs proliferation and inflammation via IL-17RB/STAT3 signaling, while IL-17C, primarily KCs-derived, forms self-amplifying inflammatory circuits and contributes to KC hyperproliferation [143], making both potential therapeutic targets in PSO and other inflammatory skin diseases. Here, IL17C is linked to inflammatory skin disease.