CD19 and Abnormal intestine morphology: Moreover, in an independent experiment, we also observed that daily oral TUDCA supplementation for one week significantly reduces the severity of SI enteropathy in CD19−/− mice (Fig. 4C and Supplementary Fig. S8), with the most pronounced effect being alleviation of crypt hyperplasia and villous blunting in TUDCA-treated CD19−/− mice (Fig. 4D).