EPHA2, EPHB4, and EPHB6 represent the most extensively studied members of the EPH/ephrin system in BC, while the expression of EPHA2-7, EPHA10, EPHB2, EPHB4, EPHB6, ephrin-A1, ephrin-A3, and ephrin-B1 in BC samples clinically correlates with the immunohistochemistry (IHC)-based groups, grading, staging, and survival. This evidence concerns the gene EFNA3 and breast cancer.