To evaluate the effect of lactate on breast cancer cells, glycolytic activity (ECAR and basal glycolysis) was assayed in stable MCF7 overexpressing POU1F1 cells before and after treatment with either a pharmacological LDHA inhibitor (GSK2837808A, referred as LDHAi, 10 μM for 24 h) or after genetic LDHA knockdown (shLDHA, Supplementary Fig. S4C). The gene discussed is LDHA; the disease is breast cancer.