The function of GPER1 was validated both <i>in vitro</i> (using a free fatty acid-induced hepatocyte steatosis model treated with the GPER1 agonist G1 or antagonist G15) and <i>in vivo</i>, with assessments of lipid metabolism-related genes, reactive oxygen species, and apoptosis. This evidence concerns the gene GPER1 and steatosis.