JAGN1 is the human ortholog of a gene originally identified in Drosophila melanogaster. It is a transmembrane protein that functions in the early secretory pathway and is necessary for neutrophil differentiation and survival. Individuals with mutations in the JAGN1 gene causes aberrant myeloid cell homeostasis and severe congenital neutropenia (SCN) (1). JAGN1-mutant granulocytes are characterized by ultrastructural defects, aberrant N-glycosylation of multiple proteins, and increased apoptosis (1). Mice lacking this gene could not mount and efficient neutrophil-dependent immune response to a human fungal pathogen (2).