TMPRSS2 and obesity due to melanocortin 4 receptor deficiency: As shown herein, the concomitant expression of TMPRSS2, ADAM17, and NRP1 in adipose tissue—receptors that become elevated in obesity and, in the case of TMPRSS2 and ADAM17, remain elevated after weight loss—likely amplifies SARS-CoV-2 tropism and infectivity in adipose tissue, even when ACE2 levels decrease following weight loss.