Maruyama Y, et al. - The clinicopathologic characteristics of CD44v9 positive cells in patients with duodenal adenocarcinoma (DA) were determined, which showed the impact of a mononuclear cell infiltration and MUC6 expression on CD44v9 expression in DA. Moreover, CD44v9 positive cells exhibited a low mitotic activity and resisted apoptosis. Thus, CD44v9 positive cells exhibit cancer stem cell (CSC)-like properties in DA.