MTHFD2 and cancer: A T cell cytotoxicity assay based on LDH release (Fig. 2l and Supplementary Fig. 2c) or Real-Time-Cell-Index analysis (Supplementary Fig. 2d) showed aggravated cytolysis in MTHFD2 KD (Fig. 2l) or KO (Supplementary Fig. 2b, c) cancer cells, which was significantly reversed by the exogenously expressed PD-L1.