SEC1P and colitis: Higher expression of Dr5 was observed in Sec1−/− mice with induced colitis relative to WT animals receiving the same treatment, at a level approaching the borderline of significance (Fig. 4A, p = 0.074), suggesting that expression of Dr5 was negatively regulated by the presence of Sec1. Western blot assay also showed a significantly higher expression of DR5 in Sec1−/− mice treated with DSS than that of the colitis or healthy WT mice (Fig. 4B).