TGFB1 and breast cancer: On one hand, in the bone microenvironment, TGF-β leads to liver, gastric, melanoma, prostate, renal, glioblastoma, leukemia and bladder cancer proliferation via the downstream activation of the MAPK/ERK and PI3K/Akt, and induces breast cancer metastasis via activation of the Wnt pathway (Bellomo et al., 2016; Futakuchi et al., 2019).