Given that CCL18 has been involved in peritoneal fibrosis in PD patients [15, 20, 22] we tested the effect of paricalcitol in the production of CCL18 by human pMΦs isolated from PD effluents drawn from patients suffering from peritonitis and cultured with various doses of nontoxic concentrations of Zemplar as a source of paricalcitol or vehicle (supplementary Figure 2). This evidence concerns the gene CCL18 and peritonitis.