Another study found that miR-421 was decreased in diabetic patients compared to controls, especially in patients with a normal or overweight body mass index (BMI) [52]; this miRNA was linked to obesity as well as to angiotensin-converting enzyme 2 (ACE2) regulation, which has been linked to viral infections such as SARS-CoV-2 infection [52]. This evidence concerns the gene ACE2 and obesity due to melanocortin 4 receptor deficiency.