GDF15 and pachyonychia congenita: The mean plasma concentration (after log transformation) of NGAL, MIC-1 and CA19-9 were all significantly higher in PC patients (111.1 ng/mL, 4.5 ng/mL, and 219.2 U/mL) than in the healthy controls (67.4 ng/mL (p = 0.01), 1.5 ng/mL (p = 0.003), and 31.5 U/mL (p = 0.001)).