Exhibits arylsulfatase activity and highly specific endoglucosamine-6-sulfatase activity. It can remove sulfate from the C-6 position of glucosamine within specific subregions of intact heparin. Diminishes HSPG (heparan sulfate proteoglycans) sulfation, inhibits signaling by heparin-dependent growth factors, diminishes proliferation, and facilitates apoptosis in response to exogenous stimulation. Binds 1 Ca(2+) ion per subunit. Optimum pH is 7.0-8.0. Also localized on the cell surface. Expressed at highest levels in testis, stomach, skeletal muscle, lung, kidney, pancreas, small intestine and colon. It is also detected in normal ovarian surface epithelial cells. Down-regulation seen in ovarian carcinoma cell lines, ovarian cancers, breast, pancreatic, renal and hepatocellular carcinoma cell lines. The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity. Belongs to the sulfatase family.