INS and obesity due to melanocortin 4 receptor deficiency: In terms of MODY and type 2 diabetes, the similarities include overlap in the age of onset and negativity for antibodies, and treatment generally does not require long-term insulin; however, differences are also notable, more adolescent patients with type 2 diabetes with obesity have metabolic syndrome, and insulin function is mainly caused by insulin resistance; by contrast, patients with MODY are generally not obese and have no metabolic syndrome, and islet function defects are mainly caused by insulin secretion defects.