When 27.8 ng/ml of ENO1 was used as cutoff for diagnosing PC, the sensitivity and specificity of diagnosis were 75.8% and 88.2%, respectively, and improved to 94.5% and 82% in combination with CA19-9, which was better than the sensitivity of CA19-9 (70–84.9%) [5]. The gene discussed is ENO1; the disease is pachyonychia congenita.