MTNR1B and Insulin resistance: Based on GWAS, there are reports about that the G-allele of MTNR1B rs10830963 associated with defective early insulin response, beta-cell dysfunction and hepatic insulin resistance in Europeans [13], [14], and Lyssenko et al. have showed the pathogenic effects of MTNR1B were likely exerted via a direct inhibitory effect on beta cell [12], the particular physiological pathway of MTNR1B in glucose metabolism has not been identified, yet it is interesting that the genetic variants within the MTNR1B region have different influence on glucose levels during pregnancy.