To evaluate the possible biological effects of ARRDC3 in H. pylori–associated gastritis in vivo, we evaluated the inflammatory response in gastric mucosa on day 28 p.i. Compared with WT mice, Arrdc3–/– mice showed significantly less inflammation (Figure 4, A and C) and less expression of proinflammatory cytokines IL-6 and TNF-α in gastric mucosa (Figure 4A and Supplemental Figure 4A). This evidence concerns the gene IL6 and gastritis.