CTLA4 and neoplasm: CD19-directed CAR is one of the most promising chimeric antigen receptor (CAR-T) T-cell therapies conceived for treatment of Acute Lymphoblastic leukemia (ALL) [39]; (iii) monoclonal antibody-based therapies targeting either tumor antigens (rituximab [40], trastuzumab [41]) or immunosuppressive mechanisms on T-cells such as ipilimumab which blocks the immuno-checkpoint CTLA-4 (cytotoxic T-lymphocyte-associated antigen-4) [42].