To explore the significance of CDK15 deficiency in breast cancer, we established CDK15-overexpression stable clones in BT549, MDA-MB-231 and MDA-MB-453 cells that have low or undetectable levels of endogenous CDK15; on the other hand, stable CDK15-knockdown clone was constructed in MCF12A normal breast cells by shRNA-mediated silencing (Figures 6A,B). Here, CDK15 is linked to breast cancer.