TGFB1 and neoplasm: The activation of the RANK-RANKL signaling pathway leads to osteoclast activation, resulting in excessive bone resorption and the release of bone matrix growth factors such as transforming growth factor-β1 (TGFβ1), insulin-like growth factor-1 (IGF1), fibroblast growth factor (FGF) or bone morphogenetic protein (BMP), which in turn promote tumor cell proliferation and further bone destruction [96].