In breast cancer, different subsets of CSCs were identified based on ALDH1, CD44, and CD24; and the two subpopulations (epithelial-like ALDH1+, mesenchymal like CD44+/CD24–) were shown to be capable of inter converting among themselves as well as give rise to non-CSCs (Liu et al., 2014). This evidence concerns the gene ALDH1A1 and breast cancer.