Figure 1a showed that serum MUC5AC in patients with PC (210.1 [100.5–423.8] ng/mL) presented higher levels than those in controls (HC, 60.8 [37.8–81.3] ng/mL; BC, 86.4 [48.4–108.2] ng/mL; CDL, 91.8 [68.0–127.4] ng/mL; CP, 95.1 [59.7–160.3] ng/mL). This evidence concerns the gene MUC5AC and pachyonychia congenita.