PDCD1 and psoriasis: Remarkably, our data demonstrated a specific impairment in the differentiation of Tc17 cells within the epidermis of Lztr1-deficient mice (Fig. 4c–e), accompanied by decreased expression of T activation-related proteins in psoriasis, such as CTLA-4, PD-1, IL22 and TNF-α (Fig. 4f–h)12,38,39.