Clinical trials of several FGF21 analogues and mimetics (Supplementary Data 4) have led to considerable improvements in conditions including dyslipidaemia, hepatic fat fractions and serum markers of liver fibrosis in NASH patients, but the primary end points of glycemic control have not been met, suggesting divergence of FGF21 biology in humans32. Here, FGF21 is linked to inherited lipid metabolism disorder.