DPP4 and metabolic dysfunction-associated steatotic liver disease: Hepatokines, including retinol fibroblast growth factor 21 (FGF21), high-mobility group box 1 (HMGB1), dipeptidyl peptidase 4 (DPP4), binding protein 4 (RBP4), alpha 2-HS glycoprotein (ASHG or FETUA), sex hormone binding globulin (SHBG), leukocyte cell-derived chemotaxin 2 (LECT2), and follistatin (FST), are involved in driving NAFLD by interaction with NF-κB (Figure 1).