The main function of the immune system’s T-cells is to identify and eliminate infected or abnormal cells within the body. These cells are a type of white blood cell and play a critical role in the adaptive immune response by recognizing specific antigens. CD4+ T-cells help orchestrate the immune response, while CD8+ T-cells directly kill infected cells. T-cells enhance the body's ability to combat pathogens and provide lasting immunity, making their function essential for overall health.