Figure 2.

Causes of Crohn’s disease (CD). Genetic susceptibility is one of the important causes of CD patients. Disturbances of the microflora and environmental factors can cause abnormal immune responses, including innate and adaptive immunity, leading to intestinal inflammation. Disease outbreaks are related to environmental factors such as antibiotic use, stress and smoking. ILCs are activated by cytokines and cell surface-bound molecules to produce distinct sets of cytokines with important consequences for tissue homeostasis and disease. ILCs display a high degree of plasticity and can trans-differentiate depending on the inflammatory environment (TL1A, TNF-like ligand 1A).