Because the effects of halofuginone against cancer and fibrosis diseases are mainly associated with its ability to inhibit the TGF-β signaling pathway and because we demonstrated that blocking TGF-β is a promising therapeutic strategy against tumor progression of osteosarcoma, the aim of this work was to evaluate the effect of halofuginone on osteosarcoma progression and metastatic development. Here, TGFB1 is linked to cancer.