CD4 and gastroenteritis: Deletion of T cell Atg16L1 in CKO mice resulted in a dramatic reduction in the number of CD4+ T cells and Treg cells in the intestinal lamina propria (LP), a significant reduction in the frequency of CD4+ and CD8+ T cells in the peripheral lymphoid organs, and an abnormal type II response to dietary and microbiota antigens, leading to the spontaneous development of progressive chronic intestinal inflammation in the mice (56).