CSMD3 and obesity due to melanocortin 4 receptor deficiency: Other obesity genes in the Fat line include 2210408I21Rik, Cep250, Fam81b, Il6st, Mamld1, Nbas, Pth1r, Sema4d, and Slco1b2. Meanwhile, in the Lean line these are Alg8, Alpk2, Aspm, D430041D05Rik, D630045J12Rik, Dock9, Gpr15, Phldb1, and Zfp462. Worth mentioning is Csmd3, a gene with the highest number of SNPs in the Lean line (shown in Supplementary Table S3).