In normal and premalignant breast cancer cells where TGF-β inhibits cell proliferation, they express low level of TβRII and EV-TβRII, whereas in high-metastatic breast cancer cells where TGF-β loses tumor suppressive responses and becomes a tumor-promoting factor, they express high level of TβRII and EV-TβRII. Here, TGFBR2 is linked to breast cancer.