Molecular and cellular biology of small-bowel mucosa.

Study of the molecular and cellular biology of the small-intestinal mucosa is providing insights into the remarkable properties of this unique tissue. With its structured pattern of cell proliferation, differentiation, and apoptosis, and its ability to adapt following exposure to luminal nutrients or injury from surgery or pathogens, it functions in a regulated but responsive manner. We review recent publications on factors affecting development, gene expression, cell turnover, and adaptation.