An initial study of 34 subjects with obesity showed a 6-fold increase in SAA expression in subcutaneous WAT compared with 27 lean controls; this was associated with 20-fold higher expression from adipocytes than the WAT stromal vascular fraction (96), which contains pre-adipocytes, immune cells, and vasculature. The gene discussed is SAA2; the disease is obesity due to melanocortin 4 receptor deficiency.