INS and diabetes mellitus: Insulin, a peptide hormone and growth factor, which is critical in patients with diabetes because it promotes both the healing of injured skin by stimulating the signal of proliferation and migration and growth factor release through the stimulation of endothelial cells, fibroblasts, and keratinocytes (Gurtner et al., 2008; Brem and Tomic-Canic, 2007; Wertheimer et al., 2001).