The article reviews the role of CD8+ T cells in the immune response to pathogens, focusing on their recognition of antigen, expansion, differentiation, and function. CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs), play a crucial role in mounting an effective immune response by expanding and differentiating into effector cells that can recognize and kill infected or transformed cells. The review highlights the importance of interactions between CD8+ T cells and antigen-presenting cells (APCs) in lymphoid organs, as well as at peripheral sites of infection. It discusses the molecular pathways and transcriptional regulators involved in the differentiation of CD8+ T cells, including the roles of IL-2, Blimp-1, and other cytokines. The article also explores the regulatory functions of CD8+ T cells, such as the secretion of the immunosuppressive cytokine IL-10 to prevent excessive tissue damage. Finally, it emphasizes the dynamic nature of CD8+ T cell responses and the need for further research to understand the full extent of their functions in protecting against immunopathology.The article reviews the role of CD8+ T cells in the immune response to pathogens, focusing on their recognition of antigen, expansion, differentiation, and function. CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs), play a crucial role in mounting an effective immune response by expanding and differentiating into effector cells that can recognize and kill infected or transformed cells. The review highlights the importance of interactions between CD8+ T cells and antigen-presenting cells (APCs) in lymphoid organs, as well as at peripheral sites of infection. It discusses the molecular pathways and transcriptional regulators involved in the differentiation of CD8+ T cells, including the roles of IL-2, Blimp-1, and other cytokines. The article also explores the regulatory functions of CD8+ T cells, such as the secretion of the immunosuppressive cytokine IL-10 to prevent excessive tissue damage. Finally, it emphasizes the dynamic nature of CD8+ T cell responses and the need for further research to understand the full extent of their functions in protecting against immunopathology.