CD8A and obesity due to melanocortin 4 receptor deficiency: Studies in carcinogen-induced or neoantigen-expressing transplant models of other tumor types harboring potent T cell neoantigens have suggested that HFD-induced obesity suppresses both the number and function of CD8+ cytotoxic T cells (Wang et al, 2019; Dyck et al, 2022), due in part to differential fatty acid uptake and partitioning between tumor and T cells within the tumor microenvironment (Ringel et al, 2020).