ERBB2 and breast cancer: Thus, our data revealing higher correlation rates between EPHA4 and TGBR2 in both basal and luminal B tumors (compared to luminal A and HER2) is consistent with the fact these tumors are more aggressive and exhibit a higher rate of metastasis and support a role for TGFβ/EPHA4 in the migratory/invasiveness of breast cancer.