May play a role in sequestering potentially toxic fatty acids and their peroxidation products, or it may be involved in the maintenance of the impermeable lipid layer of the eggshell. From muscle into the perienteric fluid. Expressed in presumptive hypodermal cells by the comma stage and in posterior body wall muscle cells by the two-fold stage. From L1 to adult stages, expression continues in body wall muscle cells adjacent to the pseudocoelom, while hypodermal expression is extinguished. Forms a beta-barrel structure that accommodates hydrophobic ligands in its interior. Belongs to the calycin superfamily. Fatty-acid binding protein (FABP) family.