The genome-wide genetic quantitative trait loci (QTL) analysis of GK rats revealed several loci that were related to diabetic phenotypes: Niddm1 located on chromosome 1 has a major effect on postprandial hyperglycemia, insulin release (Niddm1i region) and insulin action (Niddm1b region) (Galli et al., 1999); Niddm2 on chromosome 2 and Niddm3 on chromosome 10 affect both postprandial and fasting hyperglycemia; Niddm3 affects insulin release (Galli et al., 1996). Here, INS is linked to Hyperglycemia.