FETUB and Hepatic steatosis: Interestingly, GGT levels declined in the metformin-treated group while remaining stable in the comparison group, mirroring the pattern observed for fetuin B. As GGT is one of the components of the fatty liver index (FLI)—a validated and more robust surrogate marker for hepatic steatosis than GGT alone—we incorporated FLI into our statistical analyses and regression models (20).