KMT2A and breast cancer: There are numerous studies reporting that LSD1 is upregulated in various tumor tissue cells and tissues including retinoblastoma,9 non-small cell lung cancer,10 prostate cancer,11 breast cancer,12,13 and colon cancer.14 LSD1 is also overexpressed in MLL-rearranged leukemia as a key regulator to promote the oncogenic potential of MLL-AF9 leukemia stem cell.15 MLL gene translocation is a major biomarker in acute leukemia which is typically associated with a poor prognosis.