The T1D mice received the switch components encoding gluconate-induced insulin production as naked DNA via hydrodynamic tail vein injection (Figure 5C), which is a well-established technique for efficient DNA uptake by hepatocytes (approximately 40% of the liver cells have been reported to express the exogenous genes (33)), with much lower vector delivery to other tissues, such as the heart, lungs or kidneys (33,34). This evidence concerns the gene INS and type 1 diabetes mellitus.