In addition to the effects on spontaneous intestinal tumors caused by the inherited mutated Apc gene in the Min/+ mice, the effect of obesity was also examined on tumors induced by the environmental (dietary) factor formed during cooking of meat and fish, the mutagenic, genotoxic and carcinogenic heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) [14]. Here, APC is linked to obesity due to melanocortin 4 receptor deficiency.