ANPEP and neoplasm: Subgroup analysis by patient ethnicity and tumor type (Figs. 2 and 3) showed a significant relationship between high/positive APN expression and OS in non-Asian patients (HR 1.53, 95 %CI 1.20 to 1.96), but not in Asian patients (HR 1.41, 95 %CI 0.81 to 2.46).