Relationship between clinicopathological features and CD44 expression.

The IHC procedure was done as described previously [40]. The intensity of positive staining for CD44 was evaluated as negative, weak staining, moderate staining and strong staining. For chi-square test, negative, weak and moderate staining for CD44 were considered as CD44-negative or -low expression, and strong staining of CD44 was considered as CD44-high.p<0.05 was considered significant. N0: without lymph node metastasis; N1: with lymph node metastasis; TNM: tumor, node, metastasis.