Together with eak-4 and phosphatase eak-6, negatively regulates dauer larva formation downstream of insulin-like receptor daf-2 and in parallel of age-1, pdk-1 and akt-1. Localizes to dendrite-like structure in XXXL/R cells. Membrane localization is daf-2/InsR-independent. Expressed in the 2 embryonic head hypodermal cells XXXL/R. Belongs to the protein-tyrosine phosphatase family. Predicted to be inactive as the cysteine residue involved in the catalytic reaction is a lysine at position 223.