Tumour onset of two independent MT/ShcA+/+, MT/Shc2F/2F and MT/Shc313F/313F cell lines was unaffected in CD8+/+ versus CD8−/− (Supplementary Fig. 1a,b) or IFNγ+/+ versus IFNγ−/− animals (Supplementary Fig. 1c,d). This evidence concerns the gene IFNG and neoplasm.