In IHC, 307 patients were divided into Sox2 low (n=211, 68.7%) and high (96, 31.3%) expression groups. Sox2 high expression was significantly correlated with well or moderate differentiation grade both in univariate (p=0.042) and multivariate (p=0.041, OR=0.699, 95%CI [0.495-0.986]) analyses.