Two of the most promising approaches to enhance therapeutic anti-tumour immunity are immune checkpoint blockade using monoclonal antibodies against PD-1/PDL1 and CTLA4, and adoptive cell transfer of tumour-infiltrating lymphocytes (TILs) or peripheral T cells that are genetically engineered with chimaeric antigen receptors (CARs)21–23. The gene discussed is PDCD1; the disease is neoplasm.