In recent years, many specific epitopes have been suggested as markers of stem cells and, probably, cancer stem cells, such as CD44, Musashi-1 (MSI-1), CD133, CD166, DCAMKL-1 (doublecortin and calcium/calmodulin-dependent protein kinase-like-1), ALDH-1 (aldehyde dehydrogenase 1), LRIG (leucine-rich repeats and immunoglobulin-like domains-1) and LGR-5 (leucine-rich-repeat-containing G-protein-coupled receptor 5) [14-21]. Here, LGR5 is linked to cancer.