CTLA4 and neoplasm: This has been achieved with (1) tandem CARs, with two different activating CARs recognising two different tumour antigens on the same cell, one with a CD247 signaling domain and the other with a CD28 co-stimulatory domain, or (2) inhibitory CAR (iCAR), with dual antigen recognition, but for a single tumour antigen with a signaling and co-stimulatory domain, plus a normal antigen with an inhibitory PD-1 or CTLA-4 signaling domain.