CD44 and cancer: CD44 has been proposed as an important cancer stem cell marker in several cancers.14,15 CD44 is a cell surface glycoprotein that plays roles in the adhesion of the cytoskeleton to the extracellular matrix, cell–cell interactions, and cell migration.15-17 CD44 knockdown has been reported to prevent tumor formation and clonogenesis.18 The ability of CD44+ve/CD24+ve cells to differentiate into the enterocyte, enteroendocrine, and goblet cell lineages in vitro also has been established.19 CD44 overexpression has been linked to high cancer aggressiveness and resistance.20