INS and Insulin resistance: Our finding of no differences in the glucose response to glucose load in WT male offspring of heterozygous eNOS-deficient fathers vs WT offspring of WT parents but marked differences with respect to insulin levels between WT male offspring of heterozygous eNOS-deficient fathers and controls (Figs 3, 4) suggests that paternal eNOS deficiency causes insulin resistance in the WT male offspring of male heterozygous eNOS knockout mice.