CTLA4 and cancer: Immunotherapies (checkpoint inhibitors, such as anti-PD-1 and anti-CTLA-4 antibodies), a novel strategy that uses the body's immune system to target and destroy cancer cells, have shown effectiveness in treating a variety of cancers but face certain challenges, such as limited efficacy of immune checkpoint inhibitors, an immunosuppressive tumor microenvironment, and a low mutational burden [30, 31].