In normal colon crypts, LGR5+ cells are exclusively located at the base of crypts and represents about 5–6% of the epithelial crypt cells; these cells are dramatically expanded in colon adenomas, either tubulovillous or tubular, representing >70% of total crypt cells; the proportion of LGR5+ cells is markedly increased in colorectal cancers, particularly in those that are moderately differentiated (60–95% of LGR5+ cells) and to a lower extent in those that are poorly differentiated (5–50%) [400]. The gene discussed is LGR5; the disease is colon adenoma.