Exhibits beta-glucuronidase activity in vitro despite lacking canonical catalytic Glu residues of glycosyl hydrolase 1 family enzymes (By similarity). Hydrolyzes steroid beta-D-glucuronides including estradiol-3-beta-D-glucuronide, estrone-3-beta-D-glucuronide and estriol-3-beta-D-glucuronide (By similarity). Essential for the interaction between FGF23 and FGFR1 and for FGF23-mediated regulation of renal vitamin D and phosphate homeostasis (By similarity). . The Klotho peptide generated by cleavage of the membrane- bound isoform may be an anti-aging circulating hormone which would extend life span by inhibiting insulin/IGF1 signaling. . This is the function of KL (klotho, Ensembl gene identifier ENSG00000133116).