CCL4 and pachyonychia congenita: This immune cell context was confirmed in a fully immunocompetent murine PC model, in which, in addition to the recruitment of macrophages, MDCs and granulocytes, IL30 overproduction led to the intra-tumoral influx of Tregs, as also found in both experimental and clinical tissue samples of IL30-overexpressing PC [7], and likely promoted by the upregulation of PC cell expression of Ccl4 [78], Ccl20 [30], Ccl22 [31] and Ccl28 [32], which attract Tregs.