LDHA and breast carcinoma: We have previously demonstrated that normal breast tissue, primary breast cancers and breast cancer cell lines contain subpopulations with stem cell properties that can be enriched by virtue of their expression of aldehyde dehydrogenase (ALDH) as assessed by the Aldefluor assay (Stem Cell Technologies, Inc., Vancouver, British Columbia) or by tumor initiation in NOD/SCID mice [20].