KRAS and obesity due to melanocortin 4 receptor deficiency: Nongenetic factors contain age, gender, high fat intake, obesity, alcohol, and deficiency of physical exercise.2 Kirsten rat sarcoma viral oncogene homolog (abbreviated as KRAS) signaling pathway is one of the most commonly activated pathways among genetic alterations, aggravating the occurrence and progression of intestinal neoplasms.3 The KRAS gene, situating at 12p 12.1, encodes KRAS protein pertaining to the small GTPase superfamily.