RAPA is firstly isolated in 1975 from Streptomyces hygroscopicus (Othman et al., 2016), and its clinical applications for amelioration of hepatic steatosis is due to formation of the ternary complex between 12-kDa FK506-binding protein (FKBP12) and the FKBP12-rapamycin binding (FRB) (FKBP12-rapamycin-FRB) (Flaxman et al., 2019), which allosterically inhibits the kinase activity of mTORC1. Here, FOLR2 is linked to fatty liver disease.