A 2020 study (13) found that tumors and CD8+ T cells showed different metabolic adaptations to obesity, tumor cells increase fat uptake under a high-fat diet (HFD), while tumor-infiltrating CD8+ T cells do not; These different adaptations lead to changes in fatty acid distribution in HFD tumors, thereby affecting CD8+ T cell infiltration and function; Blocking MR of tumor cells in obese mice may improve antitumor immunity. The gene discussed is CD8A; the disease is obesity due to melanocortin 4 receptor deficiency.