Paneth cells release antimicrobial products which protect the crypt from bacterial infection [4, 5], as well as providing important homeostatic factors including epidermal growth factor (EGF), Notch ligand Dll4, transforming growth factor—(TGF-)α and Wnt-signalling molecules which help maintain the LGR5+ intestinal stem cells [6]. The gene discussed is EGF; the disease is bacterial infectious disease.