ETV4 may promote cell proliferation also in other systems where it regulates a number of genes: HER2 in ovarian (SKOV-3) and breast (MDA-MB-453) cancer cell lines [62]; WT1 in CHO and COS7 cell lines [63]; cyclin D3 in MDA-MB-231 breast cancer cell line [42]; cyclin D1 in mammary tissues [64]; NOTCH1 and NOTCH4 in MCF-7, MDA-MB-231, and SKBr3 breast cancer cells [65]. The gene discussed is ERBB2; the disease is breast cancer.