ADAM17 and obesity due to melanocortin 4 receptor deficiency: We did not further explore the mechanisms leading to the absence of ACE2 mRNA expression, nor the absence ACE2 protein, in adipocytes undergoing adipogenesis, but possible explanations include overexpression of micro-RNAs targeting ACE2 (93) that can increase in obesity (94) or cleavage of ACE2 from the surface of adipocytes by a Disintegrin and Metalloprotease 17 (ADAM17) (95–97).