Multivariate analysis determined serum APN/CD13 levels (OR: 3.35, 95% CI: 1.54–7.46, P=0.006), nodal status (OR: 2.52, 95% CI: 1.11–6.84, P=0.046), metastatic status (OR: 4.23, 95% CI: 1.96–8.35, P=0.026) and TNM stage (OR: 3.27, 95% CI: 1.63–8.10, P=0.013) as independent predictors of one-year mortality in PC patients. Here, ANPEP is linked to pachyonychia congenita.