FGFR2 and breast cancer: Although GWAS from several groups has confirmed that a germ-line polymorphism in intron 2 of FGFR2 is associated with BC susceptibility [75,76,77,78], emphasizing the relevance of FGFR2 in BC development, little is known about the mechanism by which FGFR2 functions as a risk factor leading to BC.