Overexpression of LSD1 has been reported in a number of malignancies, including acute myeloid leukemia (AML) [18], neuroblastoma [19], breast cancer [20], bladder carcinoma, small cell lung cancer and colorectal carcinomas [21], suggesting that LSD1 inhibitors may have important therapeutic benefit in numerous tumors. This evidence concerns the gene KDM1A and breast cancer.