The potential links between diabetes mellitus and GCa may involve the interactions with shared risk factors (e.g., obesity, hyperglycemia, hyperinsulinemia, insulin resistance, high salt intake, smoking, etc.), Helicobacter pylori (HP) infection, medications (e.g., insulin, metformin, statins, aspirin, proton pump inhibitors, antibiotics, etc.)and comorbidities (e.g., hypertension, dyslipidemia, vascular complications, heart failure, renal failure, etc.). This evidence concerns the gene INS and diabetes mellitus.