High aldehyde dehydrogenase activity identifies tumor-initiating and metastasis-initiating cells in human prostate cancer. by van den Hoogen, C, van der Horst, G, Cheung, H, Buijs, J, Lippitt, J, Guzmán-Ramírez, N, Hamdy, F, Eaton, C, Thalmann, G, Cecchini, MG, Pelger, R, van der Pluijm, G