ABCG5 and neoplasm: Additional studies have related tumor budding to increased expression of putative stem cell markers CD133 and ABCG5, as well as of beta-III tubulin, a protein involved in migration, CXCL12, a stromal cell-derived factor involved in chemotaxis and angiogenesis, hMena, a marker of cell motility and cathepsinB linked to dedifferentiation [57,60-63].