ULK1 and breast cancer: ULK1 expression was lower in the highly metastatic cell lines (MDA-MB-231 and BT-549) than those in the low metastatic cell lines (MCF-7, MDA-MB-453, and Bcap-37) (Fig. 1a), suggesting that ULK1 expression is negatively correlated to the metastatic potentials of human breast cancer cells.