NOTCH1 and breast cancer: On the basis of our findings that Notch1/TAZ axis induces glycolysis, which leads to the accumulation of glycolytic metabolites in tumor cells and increased extracellular level of lactate (Fig. 1e) and a previous report demonstrating that extracellular lactate inhibits cytotoxic T-cell activity in breast cancer [23], we next asked whether extracellular lactate modulates cytotoxic T cell-related functions in lung cancer cells.