Involved in the suppression of bile acid biosynthesis through down-regulation of CYP7A1 expression, following positive regulation of the JNK and ERK1/2 cascades. Stimulates glucose uptake in adipocytes. Activity requires the presence of KLB and FGFR4. Interacts with FGFR1, FGFR2, FGFR3 and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by KL, KLB and heparan sulfate glycosaminoglycans that function as coreceptors. Interacts with KL; this interaction is direct. Interacts with KLB; this interaction is direct. Interacts with FGFR4 in the presence of heparin, KL or KLB. Interacts with MALRD1 (PubMed:23747249). Expressed in fetal brain, cartilage, retina, and adult gall bladder. Induced by the bile acids receptor NR1H4 that binds and activates a NR1H4-responsive element within intron 2. Contrarily to other members of the family that can bind several FGF receptors FGF19 is specific for FGFR4. Belongs to the heparin-binding growth factors family.