The colorectum is a major organ in both malignant and nonmalignant diseases. Cells that line the colonic mucosal surface form a major mechanical barrier that separates the host’s internal milieu from the external environment. In addition to the well-established role of epithelial cells in ion transport; these cells appear to function as an integral component of the mucosal immune system. Human colonic epithelial cells (HCoEpiC) can process and present antigens to T cells in vitro. They also respond to a broad array of cytokines with altered gene expression and growth characteristics. In addition, normal colonic epithelial cells express the α3, α5, α6, β1 and β4 integrin.