PECAM1 and psoriasis: Histological and immunohistochemical analysis of skin tissue from mice of both genotypes with antibodies to CK14, CD68 and CD31 (markers of early keratinocytes, macrophages, and endothelial cells, respectively) revealed no differences in pathology of psoriasis-like lesions (Fig. 3b and Supplementary Figs S3b and S4b).