The means of X1: gender and X2: age, X3: height, X5: previous therapy with interferon, X8: initial dose of Ribavirin, X9: serum creatinine, X15: ALT, X16: Diabetes mellitus, X18: HCV RNA level before treatment were also more than 1, which indicates that they have non-linear relationships with response to therapy. Here, GPT is linked to diabetes mellitus.