At several of the ER+ risk loci, including the 10q26.13-rs2981579 (FGFR2) and 14q13.3-rs2236007 (PAX9) risk loci, we observed interaction peaks that were restricted to the two ER+ breast cancer cell lines and the normal breast epithelial cell line (Fig. 2a and c). Here, FGFR2 is linked to breast cancer.