ALDH1 is a marker of normal and malignant human mammary stem cells and a predictor of poor clinical outcome.
Ginestier C, Hur MH, Charafe-Jauffret E, Monville F, Dutcher J, Brown M, Jacquemier J, Viens P, Kleer CG, Liu S, et al. Cell Stem Cell. 2007 Nov; 1(5):555-67.