T cell response refers to the immune response mediated by T cells, a type of white blood cell that plays a key role in the adaptive immune system. When the body is exposed to a pathogen or foreign antigen, T cells are activated and differentiate into various subtypes, such as cytotoxic T cells that directly kill infected cells and helper T cells that coordinate the immune response by activating other immune cells. T cell response is crucial for recognizing and clearing pathogens, as well as providing long-term immunity through the generation of memory T cells. Dysregulation of T cell response can lead to autoimmune diseases, allergies, and chronic infections. Researchers study T cell response to understand how T cells recognize and respond to antigens, how they differentiate into effector and memory cells, and how they are regulated in health and disease. This research helps in the development of vaccines, immunotherapies, and treatments for immune-related diseases.