The cytotoxic T-lymphocyte assay showed that deficiency of autophagy significantly reduced the percentage of lysed (cleaved caspase-3+ and LDH+) MDA-MB-231 cells when the tumour cells were co-cultured with CD3/CD28-activated human HLA-A2+ T lymphocytes under both normoxic or hypoxic conditions, and this decrease was markedly reversed by recovery of autophagy (Fig. 1a–d, Supplementary Fig. 2g–h). This evidence concerns the gene CD28 and neoplasm.