S100A9 and systemic sclerosis: In our skin data, EREG-expressing (EREG+) APC in SSc samples showed elevation of characteristic markers of DC3, including FCN1 (p=4.78E-08) and VCAN (p=1.20E-14), interferon response (APOBEC3A, p=9.08E-16), and higher expression of the alarmins S100A9 (p= 6.15E-07) and S100A8 (p=3.24E-05) compared to healthy EREG+ APC and SSc and healthy EREG− APC (Fig. 2e).