FAS and digestive system infectious disorder: Yersinia pestis, the causative agent of the disease plague, prevents Fas induction by cleaving and inactivating FasL on the surface of effector cells, while enteropathogenic Escherichia coli (EPEC), a cause of gastrointestinal infections, post-translationally modifies FADD within target cells to arrest Fas-induced apoptosis (Figure 1).