TOP2A and breast cancer: Among them, 5 (TOP2A, HER3, CDC25B, MCM2 and TUBB) are from breast cancer cell lines (Table 3) and, in particular, HER2 positive cells (ZR7530 is [ER+PR−]HER2+, HCC2218 and BT474 are [ER−PR−]HER2+78).