Tyrosine protein phosphatase (By similarity). Acts probably as a transcription regulator in the embryonic and postembryonic development of several tissues including pharynx, vulva and gonads (PubMed:16154558). Required for the development of anterior tissues during late embryogenesis (PubMed:16154558). Together with ceh-34, required to specify the coelomocyte fate in embryonic and postembryonic precursors (PubMed:19427847). In the anterior part of the embryo, prevents apoptosis in cells that are not fated to die (PubMed:16154558). Together with ceh-34 activates proapoptotic factor egl-1 expression to promote motor neuron M4 sister cell apoptosis (PubMed:20713707). Also promotes apoptosis of I1 pharyngeal neuron sister cell (PubMed:20713707). Plays a role in locomotion and fertility (PubMed:16154558). May play a role in resistance to heat and oxidative stresses (PubMed:25108328). May cooperate with the transcription factors vab-3 and ceh-32 to repress transcription factor ets-5 expression in non BAG neuronal cells (PubMed:30890567). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Binds 1 Mg(2+) ion per subunit. Interacts (via C-terminus) with ceh-34 (via N-terminus). Expressed in body wall muscles (PubMed:25108328). Expressed in BAG sensory neurons and in other head neurons (PubMed:30890567). Expression starts at the embryonic bean stage in several anterior cells and continues until hatching (PubMed:16154558). Between the 1.5-fold and pretzel embryonic stages, expressed in a subset of pharyngeal cells and several anterior body wall muscle cells (PubMed:16154558). Expressed in the M lineage-derived coelomocyte precursor cells M.dlpa and M.drpa and in the 6 differentiated coelomocytes throughout development (PubMed:19427847). Expressed in the M4 motor neuron sister cell (PubMed:20713707). RNAi-mediated knockdown results in severe lethal arrest at an early larval stage (PubMed:16154558). The pharyngeal structure is disorganized and the anterior tip is thinner (PubMed:16154558). The phenotype is more severe in a pax-6 (ju468) mutant background (PubMed:16154558). RNAi-mediated knockdown in L1 larvae causes a decrease in resistance to heat or oxidative stresses characterized by a reduced lifespan, reduced heat shock protein hsp-16.2 expression and increased reactive oxygen species (ROS) production (PubMed:25108328). Belongs to the HAD-like hydrolase superfamily. EYA family.