IL17A and psoriasis: IBI112 targets the IL-23/IL-17 axis, which is involved in the pathogenesis of psoriasis. By neutralising the IL23p19 subunit of IL-23, IBI112 blocks IL-23 from binding to its receptor, which subsequently inhibits downstream STAT3 phosphorylation. This reduces IL-17 production, which effectively decreases inflammation and skin thickness [219].