TGFB1 and neoplasm: However, running counter to this notion, in a BMET model using TGFβRII null ER+ MCF-7 variants lacking Smad signaling, which to our knowledge, is the only other study to examine a role for TGFβ in ER+ BMET, 1D11 antibody treatment did not alter progression of ER+ BMETs, which, interestingly, also had few tumor-associated osteoclasts, suggesting that myeloid TGFβ signaling may be insufficient to drive osteolytic BMET progression in the absence of tumoral TGFβ signaling [36].