In Drosophila, evidence suggests that 20E mediates cellular immunity (26) and regulates a subset of antimicrobial peptides (AMPs) involved in antibacterial defense through peptidoglycan recognition protein LC (PGRP-LC)-dependent and PGRP-LC-independent mechanisms of the immunodeficiency (IMD) pathway activation (23, 24). Here, PGLYRP1 is linked to immunodeficiency disease.