Acts as a ligand for the receptor-type guanylate cyclase Gyc76C (PubMed:21893139). Stimulates Gyc76c-dependent cGMP production and modulates the IMD innate immune pathway in response to salt stress by inducing nuclear translocation of NF-kappa-B protein Rel which leads to increased expression of the antimicrobial peptide diptericin (PubMed:21893139). Does not appear to play a role in Gyc76C-mediated wing development (PubMed:26440503). MTYamide peptide: Expressed in the larval CNS (at protein level). NAP peptide: Expressed in the larval CNS (at protein level). IPNamide peptide: Expressed in the ventral ganglion of the third larval instar and adult brain (at protein level). Occasional ectopic branching from the posterior crossvein.