One study evaluating patients with T1DM with and without PDN found that those with PDN had higher prescribed doses of insulin, hemoglobin A1c (HbA1c) levels, and TNF receptor superfamily member 1 (TNFRSF1A) and 2 (TNFRSF1B) levels [104]. The gene discussed is INS; the disease is type 1 diabetes mellitus.