EDN1 and rheumatoid arthritis: Interestingly, the ability of serum E-selectin, ICAM-1, and ET-1 levels to discriminate patients with RA-ILD+ from those with RA-ILD− was confirmed by performing ROC curve analysis (AUC: 0.78, p < 0.01; AUC: 0.72, p = 0.01; AUC: 0.77, p < 0.01, respectively, Figure 1B, Table 1).