MTHFD1L and cancer: In particular, CRISPR perturbation screens reveal that loss of mitochondrial one-carbon (mito-1C) metabolism enzymes, mitochondrial serine hydroxymethyltransferase 2 (SMHT2) and methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L), sensitizes cancer cells to eprenetapopt—an insight that can be exploited in vivo to sensitize tumors to eprenetapopt with serine and glycine (SG) dietary restriction.