When the cut-off values of CA19-9, ULBP2 and MIC-1 were set at 18.44 U/ml, 94.08 pg/ml and 642.83 pg/ml respectively, MIC-1 was found to have the highest sensitivity (89.9%), while CA19-9 had the highest specificity (96.8%) in distinguishing PC patients from NC (Fig. 1B; Table III). The gene discussed is ULBP2; the disease is pachyonychia congenita.