CD8 T cells, also known as cytotoxic T cells, are a type of immune cell that play a crucial role in the body's defense against infections and cancer. These cells are able to recognize and kill infected or abnormal cells by releasing toxic molecules. CD8 T cells are essential for the body's adaptive immune response, as they can effectively destroy pathogens that have evaded other immune mechanisms. Research in the field of CD8 T cells focuses on understanding their activation, function, and regulation, as well as developing strategies to enhance their activity for therapeutic purposes, such as in cancer immunotherapy.