Table 2.

Effects of deletions affecting insulin receptor signaling in mice.

Protein deleted	Resulting β-cell function	Insulin action	Effect on glycemic control
Irs1	Increased β-cell mass	Mild defects	Normal
Irs2	Decreased β-cell mass	Impaired insulin action	Frank diabetes
Akt-2	Normal	Impaired signaling	Hyperglycemia
Slc2a4	Normal	Moderate insulin resistance	Hyperglycemia (in males)
Muscle-specific Slc2a4	Normal	Very insulin-resistant	Impaired glucose tolerance; diabetes in a subset
Fat-specific Slc2a4	Normal	Reduced suppression of gluconeogenesis	Impaired glucose tolerance; diabetes in a subset

Abbreviations: Akt-2, RAC-β serine/threonine-protein kinase; Irs, insulin receptor substrate; Slc2a4, solute carrier family 2, member 4 (previously termed Glut4).