In contrast, EP2 is elevated in Th17 cells from patients with RA but is not significantly increased in patients with AS (p = 0.0129; 14.4 ± 1.3 in RA vs. 9.9 ± 0.97 in HC; 11.6 ± 1.5 in AS; Fig. 1h). This evidence concerns the gene PTGER2 and rheumatoid arthritis.