GCK and type 2 diabetes mellitus: These efforts confirmed the GCK, G6PC2 and MTNR1B associations, and uncovered associations of fasting glucose with single nucleotide polymorphisms (SNPs) in or near DGKB, GCKR, ADCY5, MADD, CRY2, ADRA2A, FADS1, PROX1, SLC2A2, GLIS3, C2CD4B and the type 2 diabetes genes TCF7L2 and SLC30A8. In addition, SNPs in or near IGF1, GCKR and perhaps IRS1 have been found to influence fasting insulin concentrations, a surrogate for insulin resistance.