Comparing the body weight of AAV-injected Sim1-cre mice versus AAV-injected wild-type littermates, we found that overexpression of Snca (Fig. 5g) and Igsf8 (Fig. 5h) caused an exacerbation of HFD-induced obesity, whereas overexpression of Spata2, Pole4, Fndc4, Smim12, or Arrb1 had no impact on body weight (Supplementary Fig. 8g–k). This evidence concerns the gene IGSF8 and obesity due to melanocortin 4 receptor deficiency.