By immunohistochemistry, both Tcf7l1 and LCN2 were strongly expressed in psoriasis vulgaris, verrucous epidermal nevus, condyloma acuminatum and SCC (Broders’ grade I) while negative or slight expression was seen with normal skins, seborrheic keratosis, Bowenoid papulosis and basal cell carcinoma (BCC) (Figure 1a). This evidence concerns the gene TCF7L1 and psoriasis vulgaris.