CCNE1 and breast cancer: For breast cancer cell lines, qRT-PCR and western blot analysis confirmed that CCNE1 expression was higher in MDA-MB-231 and SUM1315 (two TNBC cell lines) than other types of breast cancer cell lines (MCF-7, ZR-75-1, and T47D) and normal breast epithelial cell line (HBL-100) (Figures 1I,J).