The review article discusses the role of cytotoxic CD8+ T cells in cancer and cancer immunotherapy. It highlights the importance of the interaction between the innate and adaptive immune systems in anticancer immunity, with CD8+ T cells being the most powerful effectors. The article covers the mechanisms of T-cell activation, including the engagement of the T-cell receptor (TCR) complex and the role of co-stimulatory signals from CD28 receptors. It also explores the development of chimeric antigen receptors (CARs) for adoptive cell transfer therapy, which has shown significant success in treating certain cancers. The review discusses the challenges and side effects of CAR T-cell therapy, such as cytokine release syndrome, and potential solutions like gene-editing tools and synthetic receptors. Additionally, it examines the tumor microenvironment (TME) and immune escape mechanisms, including the downregulation of MHC molecules and the upregulation of immune-checkpoint ligands by tumor cells. The article concludes by discussing the future of cancer immunotherapy, emphasizing the potential of combinatorial regimens and personalized treatments.The review article discusses the role of cytotoxic CD8+ T cells in cancer and cancer immunotherapy. It highlights the importance of the interaction between the innate and adaptive immune systems in anticancer immunity, with CD8+ T cells being the most powerful effectors. The article covers the mechanisms of T-cell activation, including the engagement of the T-cell receptor (TCR) complex and the role of co-stimulatory signals from CD28 receptors. It also explores the development of chimeric antigen receptors (CARs) for adoptive cell transfer therapy, which has shown significant success in treating certain cancers. The review discusses the challenges and side effects of CAR T-cell therapy, such as cytokine release syndrome, and potential solutions like gene-editing tools and synthetic receptors. Additionally, it examines the tumor microenvironment (TME) and immune escape mechanisms, including the downregulation of MHC molecules and the upregulation of immune-checkpoint ligands by tumor cells. The article concludes by discussing the future of cancer immunotherapy, emphasizing the potential of combinatorial regimens and personalized treatments.