CTLA4 and cancer: It primarily aims to boost the host's natural defense system to combat cancer malignancies by utilizing components of immune checkpoint blockades (ICBs), mainly programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), along with elements of adoptive cellular therapies (ACTs) like Chimeric Antigen Receptor (CAR) therapy, T Cell Receptor (TCR) therapy and Tumor-Infiltrating Lymphocyte (TIL) therapy.