DPP4 and hepatocellular carcinoma: Subjects with low DPP4 expression in HCC tissues had a much lower mean survival time than those with high DPP4 expression (P=0.016, low DPP4=48.3 months vs high DPP4=68.4 months) (Figure 3A), while DPP4 was not associated with time-to-recurrence (Figure 3B) (P=0.595).