Both Type 1 diabetes mellitus (T1DM), characterized by absolute insulin deficiency due to the loss of the secretory function of pancreatic β-cells, and Type 2 diabetes mellitus (T2DM), in which there is a progressive loss of insulin secretion on the background of insulin resistance [3], are accompanied by characteristic macrovascular and microvascular complications, the latter including retinopathy, nephropathy, and neuropathy [4]. The gene discussed is INS; the disease is type 1 diabetes mellitus.