Correlation of STK33 expression with clinicopathological parameters. (A) Representative images of STK33 IHC staining in different differentiation types and corresponding H&E staining (Magnification × 400, Scale bars, 50 μm). (B) STK33 IHC score was significantly higher in non-keratinizing type than that in keratinizing type shown in A. Moreover, STK33 IHC score was significantly correlated with tumor size (C) clinical stages (D) lymph node metastasis (E). Data were expressed as the mean ± SD. * P < 0.05.