In this study, to understand the mechanisms underlying the onset of PNDM at the organism level, we induced the expression of two types of human mutant preproinsulin identified from PNDM patients, hINSC96Y (Akita mutation identified from PNDM mice introduced into human preproinsulin) and hINSLB15YB16delinsH (identified from human PNDM patients) in Drosophila tissues during development. The gene discussed is INS; the disease is permanent neonatal diabetes mellitus.