Involved in embryonic and larval development (PubMed:9472025, PubMed:20380830). Plays a role in oogenesis by regulating mpk-1 phosphorylation and oocyte maturation in response to major sperm protein (MSP) (PubMed:9472025, PubMed:20380830). During the formation of neuromuscular junctions at the larval stage, negatively regulates membrane protrusion from body wall muscles probably downstream of receptor egl-15 (PubMed:16495308). Plays a role in fluid homeostasis probably downstream of receptor egl-15 and adapter soc-1 (PubMed:11689700). Promotes vulva induction and negatively regulates fertility probably downstream of receptor let-23 (PubMed:9472025, PubMed:16547100). Negatively regulates daf-2-mediated repression of dauer formation (PubMed:16547100). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Localizes to vesicle-like structures. Expressed in embryonic cells, developing vulva, body wall muscles, head neurons and gonadal sheath cells. RNAi-mediated knockdown causes an increase in ectopic formation of membrane extensions from body wall muscles and a reduction in life span caused by early stage mortality (PubMed:16495308, PubMed:16547100). Prevents constitutive dauer formation in a daf-2 e1370 mutant background (PubMed:16547100). Belongs to the protein-tyrosine phosphatase family. Non-receptor class 2 subfamily.