CCL4L2 and pachyonychia congenita: Non-classical monocytes in the peripheral blood of PC patients had clear upregulated expression of inflammatory genes (TNF, IL1B, DUSP2, and S100A8), chemokines (CCL3, CCL3L1, CCL4L2, and CXCL8), and TFs (EGR1, FOS, JUN, and JUND) compared with HCs (Figure 5D).