IGFN1 and breast cancer: Similarly, other overexpressed genes including RNA binding motif protein 24 (RBM24), Immunoglobulin-like and fibronectin type III domain containing 1 (IGFN1), and Cytochrome P450 family 4 subfamily F member 12 (CYP4F12) may have biological contributions to tumorigenesis in Tier-1 PHTS BC but their exact roles are unclear24–28.