TGFB1 and hypertensive disorder: In this study, we observed the effects of pioglitazone on vascular fibrosis, and the expression of transforming growth factor β (TGF-β) and CTGF in spontaneously hypertensive rats (SHRs) to ascertain whether administering pioglitazone could attenuate vascular fibrosis with hypertension and to understand the underlying mechanisms.