BCL2 and immune system disorder: Apoptosis is an important mechanism that causes intestinal mucosal damage and immune disorders in intestinal inflammatory diseases.[58] FAS is a membrane receptor protein that belongs to the NGF receptor superfamily, plays a signal transduction role in apoptosis and induces apoptosis in cells expressing the Fas protein.[59] The Bcl-2 protein is a recognized apoptosis suppressor, and the Bcl-2/Bax ratio regulates the rate of apoptosis.[60] Sensitized T cells can induce colonic epithelial cell and protective Th2 cell apoptosis or even kill directly through the Fas/FasL pathway.