ERAP1 and colitis: Notably, mRNA expression levels of Anxa9 (p < 0.05), Atp2a1 (p < 0.001), and Hepacam2 (p < 0.01) were all significantly upregulated in ERAP1+/− colitis mice relative to WT colitis mice after sulfasalazine treatment (Figures 7A-C), indicating its potential role in colitis pathogenesis and therapeutic response.