Compared to non lesional psoriatic skin and normal skin the number of K10 expressing keratinocyte layers was considerably lower in lesional psoriasis epidermis (Fig. 3), indicative of disturbed keratinocyte differentiation in psoriasis as it has already been demonstrated in several reports (for a comprehensive review please see Tschachler et al., 2007). This evidence concerns the gene KRT10 and psoriasis.