CTLA4 and hematopoietic and lymphoid cell neoplasm: Antibodies targeting cytotoxic T lymphocyte-associated protein 4 (CTLA-4) [73–75], or blocking the programmed death-1–programmed death-ligand 1 (PD-1/PD-L1) axis [76–78], as well as CD47 monoclonal antibodies (mAbs) that inhibit the interaction between CD47 and signal-regulatory protein-α (SIRPα) [79–82], are immune checkpoint-blocking drugs approved to treat various solid and hematologic cancers.