THBS1 and osteosarcoma: In our study, TSP1 expression was stimulated in osteosarcoma cell lines by TGF-β1, not by other growth factors (VEGF, EGF, FGF-2), and this is accordance with previous study that TGF-β1 not EGF could stimulate TSP1 expression in osteosarcoma cell line MG63 [34].