Contributes to the transcriptional repression of cholesterol 7-alpha-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis. Probably inactive as a glycosidase. Increases the ability of FGFR1 and FGFR4 to bind FGF21 (By similarity). Interacts with FGFR1 and FGFR4 (By similarity). Interacts with FGF19; this interaction is direct. Interacts (via C-terminus) with FGF21; this interaction is direct. Contains 2 glycosyl hydrolase 1 regions. However, the first region lacks the essential Glu active site residue at position 241, and the second one lacks the essential Glu active site residue at position 889. These domains are therefore predicted to be inactive. Belongs to the glycosyl hydrolase 1 family. Klotho subfamily.