KRT19 and breast cancer: As KRT19 was upregulated in MDA-MB231 and downregulated in KU-CSLC cells, we next knocked down the expression of KRT19 by using a KRT19 specific shRNA (shKRT19) and overexpressed KRT19 (KRT19-oe) in KU-CSLC cells to investigate the function of KRT19 in breast cancer.