mortality. However, knowledge of the biological factors that influence ad libitum alcohol
intake may be incomplete. Two large studies recently linked variants in the KLB locus with
levels of alcohol intake in humans. KLB encodes β-klotho, co-receptor for the liver-derived
hormone fibroblast growth factor 21 (FGF21). In mice, FGF21 reduces alcohol intake, and
human Fgf21 variants are enriched among heavy drinkers. Thus, the liver may limit alcohol …