TGFβ1 induces THBS1 (thrombospondin-1) expression via Smad3, which contributes to invasive behavior during glioblastoma expansion [37]; TGF-β also stimulates both THBS1 and CISP/THBS2 synthesis by bovine adrenocortical cells [38]. Here, SMAD3 is linked to glioblastoma.