ERBB2 and breast cancer: Furthermore, the independent genetic variant in growth factors signalling appear to have the stronger influence on breast cancer risk via combining with other variant gene, including variant fibroblast growth factor 1 (FGF1), FGF2 and neuregulin 2 (NRG2), interacted with SNPs in platelet‐derived growth factor B (PDGFB), EGFR, HER‐2 and FGFR2 89.