PTPRC and psoriasis: Given that KCs constitutes 90% of the non-hematopoietic compartment cells in the epidermis, to explore the role of MKP-1 in KCs in the pathogenesis of psoriasis, we sorted CD45− cells (constituting of most of KCs) from IMQ-treated WT and MKP-1−/− mouse epidermis and measured the expressions of cytokines and chemokines.