IGF1 and breast cancer: The Breast and Prostate Cancer Cohort Consortium (BPC3) assessed common variation in 24 genes in the insulin and IGF pathways in European ancestry women and found no single-SNP associated with breast cancer using a threshold of P<4.7×10−5 to adjust for the total number of tested SNPs.25 Although in BPC3 gene variants in IGF1 and SSTR5 were associated with circulating levels of IGF-1, and SNPs in IGFBP3 and IGFALS were associated with circulating levels of IGFBP-3, these variants only explained a small fraction of the variation of IGF-1 and IGFBP-3 circulating levels.42