In mammary carcinoma, functionally validated CSCs (termed MaCSCs (mammary CSCs)) have been identified by profiling the expression of cell surface markers such as PROCR (P) and ESA (E) and/or by assaying aldehyde dehydrogenase (ALDH) activity.9, 10, 11, 12 Despite this insight, the underlying mechanisms that mediate the MaCSC phenotype are unclear. This evidence concerns the gene LDHA and breast carcinoma.