CDK15 and breast cancer: Although CDK15 does not regulate proliferative potential of breast cancer cells, intriguingly, CDK15-overexpressing cells lost their mesenchymal phenotype and acquired epithelial morphology (Figure S5A); conversely, CDK15-silencing MCF12A cells obtained obvious spindle-like morphology compared with vector control cells (Figure S5B), suggesting that CDK15 might be related to the regulation of cell motility.