Ay mice with ectopic overexpression of agouti peptide, an endogenous melanocortin-4 receptor antagonist, are known to become obese and insulin-independent diabetes, when bred with KK mice.15 Social isolation promotes obesity due to the primary decreased energy expenditure and the insulin-independent diabetes associated with increased expression of hepatic gluconeogenic genes in KKAy mice.15 The gene discussed is INS; the disease is diabetes mellitus.