Xu et al. (2019) have recently reported that serum FABP4 is a positive determinant of FLI in normal glucose tolerance individuals. Moreover, in a prospective study performed in healthy individuals, Jeon et al. (2013) identified that serum FABP4 levels were found associate with FLI as a predictive indicator of NAFLD. The gene discussed is FABP4; the disease is metabolic dysfunction-associated steatotic liver disease.