CD44 and neoplasm: IHC staining demonstrated the presence of (1) an EMA+/CD44+/SALL4+/NANOG+/pSTAT3+/SOX2+/OCT4− CSC subpopulation within the tumor nests (TNs); (2) a CD44+/SALL4+/NANOG+/pSTAT3+/SOX2+/OCT4− CSC subpopulation; and (3) a CD44+/SALL4+/NANOG+/pSTAT3+/SOX2+/OCT4+ CSC subpopulation within the stroma, between the TNs.