One ALK translocated (H2228), two EGFR mutant NSCLC lines (PC-9, Ma-1), two HER2-amplified (BT-474, SKBR-3) and two ER+ breast cancer lines (MCF-7, T-47D), two B-Raf mutant (COLO-800, SK-MEL-1) and two N-Ras mutant melanoma lines (SK-MEL-30, IPC-289) were exposed to TAE684, erlotinib, lapatinib, tamoxifen, vemurafenib and CI-1040, respectively, for 7 days and analyzed for the expression of ALDH1 and CD44. This evidence concerns the gene ALDH1A1 and breast cancer.