Then, we examined the differentiation markers expression by western blot in full- depth biopsies of lesional skin from psoriasis patients (n = 12) and healthy skin (n = 12), the results showed an increase in the numbers of late differentiation markers Involucrin and a decrease in K10-expressing cells in the epidermal layer reflecting abnormal differentiation in psoriasis skin lesions compared to healthy skin (Fig. 2d). This evidence concerns the gene IVL and psoriasis.