Second, the cohort was matched according to the demographic and medical characteristics of the DPP-4 inhibitor and non-DPP-4 inhibitor groups are well-matched by age, insurance range, comorbidities including HBV infection and liver cirrhosis, the use of antidiabetic medications except for DPP-4 inhibitors, the use of anti-HCV agents, and the duration of diabetes to avoid bias. Here, DPP4 is linked to diabetes mellitus.