Acts as a dual-specificity protein phosphatase, dephosphorylating tyrosine-, serine- and threonine-phosphorylated proteins (By similarity). Also acts as a lipid phosphatase, removing the phosphate in the D3 position of the inositol ring from phosphatidylinositol 3,4,5-trisphosphate (PubMed:15637588). By dephosphorylating PtdIns(3,4,5)P3 antagonizes PtdIns(3,4,5)P3 production by age-1/PI3K and thus, negatively regulates daf-2-mediated processes including dauer formation, longevity, fat metabolism, chemotaxis towards salt, thermotolerance and axon guidance (PubMed:9885576, PubMed:10209098, PubMed:10377431, PubMed:16950159, PubMed:19249087, PubMed:23995781, PubMed:10077613, PubMed:20207731). Similarly, promotes apoptosis during embryonic development by suppressing the recruitment of the prosurvival kinases akt-1/2 to the plasma membrane (PubMed:25383666). In addition, regulates Z2/Z3 germline precursor cell cycle by maintaining them arrested at the G2 stage and by controlling their growth during L1 diapause (PubMed:16631584). After sperm depletion in larvae and adult hermaphrodites, promotes germline stem cell quiescence and oocyte accumulation (PubMed:26552888). By dephosphorylating ephrin-like receptor vab-1 on tyrosine residues, negatively regulates oocyte maturation downstream of vab-1 and upstream of mpk-1, independently of daf-2 (PubMed:19853560). Plays a role in postembryonic muscle arm extensions (PubMed:18436204). Required for neurite outgrowth during AIY interneuron embryonic development (PubMed:22069193). Mainly independently of daf-2, negatively regulates vulva induction probably by inhibiting mpk-1 phosphorylation (PubMed:22916028). Both lipid and protein phosphatase activities are required for the regulation of vulva induction (PubMed:22916028). a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + phosphate H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate 1,2-dioctanoyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = 1,2-dioctanoyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + phosphate 1,2-dihexadecanoyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = 1,2-dihexadecanoyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + phosphate Interacts (via C-terminus) with vab-1 (via kinase domain); the interaction is independent of vab-1 kinase activity (PubMed:19853560). Interacts with arr-1 and mpz-1; the interaction may inhibit daf-18 (PubMed:20207731). Interacts (via C-terminus) with daf-2 (via kinase domain) (PubMed:23995781). During vulva development, localizes to the cytoplasm and the nucleus of vulva precursor cells and of vulva cells at the Pn.p stage of L2 larvae. From the Pn.px to Pn.pxx stage of L3/L4 larvae, localization increases at the plasma membrane and becomes maximal at the Pn.pxxx stage of L4 larvae. Expressed in embryo, larvae and in adult germline (at protein level) (PubMed:16481471, PubMed:22916028, PubMed:19853560). Expressed at equal levels in the 6 vulva precursor cells (VPCs) of L2 larvae and in the descendant cells of the induced VPCs (at protein level) (PubMed:22916028). Expressed in the uterus (at protein level) (PubMed:22916028). Expressed in the Z2/Z3 germline precursors, oocytes, several amphid neurons and weakly in the nerve cord (at protein level) (PubMed:19853560). Phosphorylated by vab-1 on tyrosine residues which may promote daf-18 degradation. Mutants are viable but with a shorter lifespan. They also fail to enter dauer stage under starvation conditions and 17 percent of mutants display vulval bursting (PubMed:10209098, PubMed:10377431, PubMed:20207731). Unlike in wild-type animals, germline stem cell proliferation continues following sperm depletion and Z2/Z3 germline precursors continue to proliferate during L1 diapause (PubMed:16631584, PubMed:26552888). The number of unfertilized eggs laid after sperm depletion is also increased (PubMed:26552888). Prevents constitutive dauer entry and pharynx remodeling and restores normal brood size in a daf-2 mutant background (PubMed:10209098, PubMed:10377431). Prevents increase in lifespan in an arr-1 (ok401) mutant background or in mpz-1 RNAi-mediated knockdown animals (PubMed:20207731). Suppresses the increase in ovulation rate and mpk-1 phosphorylation in distal oocytes in a vab-1 (dx31) mutant background. Restores normal axon extension of PLM neurons in a daf-2 (e1370) mutant background (PubMed:23995781). RNAi-mediated knockdown prevents arrest at the dauer larval stage in a daf-2 or age-1 mutant background (PubMed:9885576, PubMed:10077613). In addition, suppresses increased thermotolerance and fat storage and reduces daf-16 nuclear localization in a daf-2 mutant background (PubMed:19249087). Belongs to the PTEN phosphatase protein family.