In this context, chemokines and their receptors, e.g., CCL2/CCL12-CCR2, CXCL5/2/1-CXCR2, CCL3/4/5-CCR5, CCL15-CCR1, and CXCL8-CXCR1/2, are relevant for a rapid progression of PC and the recruitment of MDSCs (36, 37). Here, CXCR2 is linked to pachyonychia congenita.