Recently, Herbert and colleagues identified, following a genome-wide association study involving 86,604 SNPs, one SNP (rs7566605) situated 10 Kb 5' to the insulin-induced gene 2 (INSIG-2) which showed strong evidence for association with body mass index in multiple cohorts (OR for obesity 1.22 [95% CI 1.05–1.42]; p = 0.008 in meta-analysis of 6 cohorts). Here, INSIG2 is linked to obesity due to melanocortin 4 receptor deficiency.