The expression of ALDH1 alone or with the expression of cell surface markers CD44 or CD133, has been used to enrich a cell population with chemoresistant and stem-cell like properties in head and neck squamous cancer cells [20, 32], lung [22], colon cancer [33] and in breast cancer [24, 34, 35]. The gene discussed is ALDH1A1; the disease is malignant colon neoplasm.