PTPRC and psoriasis: The results showed a marked increase in MPO activity in the skin of mPGES-1−/− mice treated with IMQ for 3 days, correlating with the increase in the percentage of CD45-positive cells shown in Fig. 3A. These results suggest that the lack of mPGES-1 may exacerbate the symptoms of psoriasis in mPGES-1−/− mice in terms of inflammatory cell infiltration in the skin, suggesting that the presence of mPGES-1 may be protective against the pathology of psoriasis.