Anti-Steroid sulfatase antibodies are used in the immunodetection of the protein encoded by the STS gene. In humans, the canonical protein has a reported length of 583 amino acid residues and a mass of 65.5 kDa. Its subcellular localization is in the cytoplasmic vesicles and ER. A member of the Sulfatase protein family, it is known to catalyze the conversion of sulfated steroid precursors, such as dehydroepiandrosterone sulfate (DHEA-S) and estrone sulfate to the free steroid. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include ARSC1, ASC, ES, SSDD, XLI, steryl-sulfatase, arylsulfatase C, and ARSC.