Ala Litman et al. illustrated the significance of the CXCL8-CXCR2 axis in PC, which indicated that the serum CXCL8 was superior to CXCR2, C-reactive protein, classic tumor markers CA 19-9, and CEA when used as a diagnostic and predictive marker [44]. Here, CXCR2 is linked to pachyonychia congenita.