TLR4 and colitis: Colitis caused a significant increase in the expression of inflammatory and apoptotic genes, such as IL‐6, IL‐1β, TNF‐α, TLR4, INOS, NF‐κB, Bax, Bcl‐2, Caspase‐3, and Caspase‐8, that led to severe inflammation in the colitis rats, as well as infiltration of inflammatory cells and severe damage to colon tissue epithelium.