Tumor-derived cyclic adenosine monophosphate can cause DNA damage and senescence in both CD4+ T cells and CD8+ T cells and immunoglobulin-like transcript 4 and its derivative PIR-B induce T cell senescence by increasing the fatty acid synthesis and lipid accumulation in tumor cells via MAPK ERK1/2 signaling (80). This evidence concerns the gene CD8A and neoplasm.