Involved in resistance to Gram-negative bacterium S.marcescens and to bacterium Gram-positive S.aureus infection. Localizes in vesicles in the apical region of intestinal cells. Expressed in intestine, IL2 and IL6 neurons and some neurons in the head ganglia. Induced by Gram-negative bacteria S.marcescens and B.thuringiensis infection. RNAi-mediated knockdown causes a reduction in survival in response to bacterium S.aureus infection. Belongs to the glycosyl hydrolase 25 family. Lacks conserved active site residues, suggesting it has no catalytic activity.