ELANE and neutropenia: The etiology of ELANE-related neutropenia is attributed to mutations in the ELANE gene, which induce unfolded protein response-associated apoptosis at the promyelocyte stage and result in ineffective myelopoiesis.[14–17] Heterozygous mutations in the ELANE gene are reported to be found in 80% to 100% of patients with CyN.[3–6]ELANE heterozygosity has also been identified in 35% to 69% of patients with SCN.[9,19–23] A previous study reported that 187 SCN patients and 120 CyN patients had 94 and 22 mutations in the ELANE gene, respectively.