PDGFB and temporal arteritis: In addition, GCA-affected TAB showed elevated expression of TGF-β (81.0% vs 44.0%, P < 0.001), PDGFB (66.9% vs 27.8%, P = 0.023) and FGF21 (77.1% vs 9.0%, P < 0.001) in the adventitia compared with controls (Fig. 2B).