A recently proposed drug candidate for the treatment of NASH is the fibroblast growth factor 21 (FGF21) (Xu et al., 2009; Dushay et al., 2010; Verzijl et al., 2020), an autocrine hormone that induces fat oxidation and inhibits fat synthesis in the liver (Nishimura et al., 2000; Badman et al., 2007; Lundåsen et al., 2007; Feingold et al., 2012; Woo et al., 2013). Here, FGF21 is linked to metabolic dysfunction-associated steatohepatitis.