We used our animal model [14,16,17,18,19] to test this hypothesis and to also confirm the effect of TGF-β in the bone micro-E: mouse mammary tumor cell line, CL66M2 was implanted into two different sites in female mice, under the dorsal skin flap over the calvaria and into the subcutis of the back of each female mouse, generating tumor growth in the bone and subQ micro-Es. Here, TGFB1 is linked to breast cancer.