In addition to the close link between ZAG levels and obesity, very recent work performed by Stepan et al. [10], Leal et al. [11], and Tedeschi et al. [12] also demonstrates that serum ZAG levels are increased in patients with preeclampsia, hemodialysis (HD), or advanced heart failure patients compared with response controls. The gene discussed is AZGP1; the disease is obesity due to melanocortin 4 receptor deficiency.