C3 and obesity due to melanocortin 4 receptor deficiency: Immunodetection of C3 in independent human healthy and obese secretomes from VAT and SAT explants confirmed the oversecretion of C3 by visceral adipose tissue compared to subcutaneous in obesity (p = 0.05) and revealed the elevated secretion of obese VAT in relation to healthy VAT tissue (p = 0.06) (Fig. 4A).