A non-specific tyrosine phosphatase that dephosphorylates a diverse number of substrates under acidic conditions(pH 4-6) including alkyl, aryl, and acyl orthophosphate monoesters and phosphorylated proteins. Has lipid phosphatase activity and inactivates lysophosphatidic acid in seminal plasma.nIsoform 2: the cellular form also has ecto-5'-nucleotidase activity in dorsal root ganglion(DRG) neurons. Generates adenosine from AMP which acts as a pain suppressor. Acts as a tumor suppressor of prostate cancer through dephosphorylation of ERBB2 and deactivation of MAPK-mediated signaling.