FFAR1 and fatty liver disease: To explain the different effects of GPR40 KO on hepatic steatosis in LDLR-deficient mice and C57BL/6 mice, we postulated that the elevated plasma levels of FFA and cholesterol, which were observed only in GPR40 KO in LDLR-deficient mice, are responsible for the different effects of GPR40 on hepatic steatosis.