Large-scale exon resequencing around an MTNR1B SNP modestly associated with type 2 diabetes (OR between 1.10 and 1.15) identified four rare variants that led to loss of melatonin binding and signalling capacity (OR 5.67, 95% CI 2.17–14.82) [65]. The gene discussed is MTNR1B; the disease is type 2 diabetes mellitus.