The overexpression of the nine obesity-related genes (MC4R, TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2, FTO, PCSK1, and GPR120) may associate with tumor-promoting factors in some organs (head and neck, gastrointestinal tract, liver, and gallbladder). The gene discussed is MC4R; the disease is neoplasm.