For instance, T cells transduced with high-affinity T-cell receptors against specific tumour antigens in conjunction with high doses of interleukin-2 (IL-2) have shown considerable clinical responses in patients with melanoma.2 The development of antibodies that block the checkpoint inhibitory receptors PD-1 and CTLA-4 have shown remarkable results in conjunction with adoptive T-cell therapy.3, 4 However, protocols for the ex vivo expansion and manipulation of T cells before adoptive transfer remain to be fully optimised. This evidence concerns the gene IL2 and melanoma.