TNF and inflammatory bowel disease: Significantly higher levels of IL-1β (p < 0.001), IL-6 (p < 0.001), and TNF-α (p < 0.001) were found for Sec1−/− mice with DSS-induced IBD in comparison to WT animals with same conditions (Fig. 2A), confirming the suppressive role of Sec1 on systemic immune responses.