Whilst FGF10 is not expressed in the luminal epithelial cells of the normal human breast duct (Grigoriadis et al., 2006), transcription of the FGF10 gene is elevated 10% of breast carcinomas (Theodorou et al., 2004) and genome-wide association studies have identified variants near the FGF10 locus as a genetic risk factor for breast cancer susceptibility (Stacey et al., 2008). Here, FGF10 is linked to breast cancer.