Furthermore, we found that the frequency of the IGF1-19/-19 genotype was significantly higher among known BRCA1 carriers compared with other high-risk women and we have reported previously that each pregnancy up to three confers an increased risk for breast cancer before age 40 years among BRCA1 and BRCA2 carriers (Jernström et al, 1999). This evidence concerns the gene BRCA1 and breast cancer.