We found that ALDH positive colonic cells exhibit the known SC properties of anatomic localization and tumor-initiating ability: (a) immunohistochemistry identified a small subpopulation of ALDH1+ cells (∼5%) localized to the bottom of normal crypts (where SC reside) and (b) the Aldefluor assay was used to isolate a subpopulation of malignant colonic cells that generates xenograft tumors (also showing the ability for self-renewal). The gene discussed is LDHA; the disease is neoplasm.