In addition, we observed slightly higher expression of PDPN (1.0% vs 0%, P = 0.015) in the adventitia of the GCA-affected aorta and higher expression of FAP (2.6% vs 13.1%, P = 0.024) in the intima of the atherosclerotic aorta (Fig. 3A, B; Supplementary Fig. S4D, available at Rheumatology online). Here, FAP is linked to temporal arteritis.