The key challenges for the conventional adoptive T-cell therapy approach are the requirement for surgical access to at least moderate volumes of fresh primary/metastatic tumour tissue for preparation of tumour-infiltrating-lymphocytes, the potential induction of regulatory T cells within the TIL product during prolonged in vitro culture with IL-2, the complexities of screening the cellular product for tumour antigen reactivity and specificity, and the requirement that patients are fit for chemotherapy and often high-dose IL-2. This evidence concerns the gene IL2 and neoplasm.