Figure 6. Prognostic significance of SPINK6 protein expression in nasopharyngeal squamous cell carcinoma. (A–D) Representative photomicrographs of SPINK6 protein expression by IHC magnified 200 times under a light microscope. (A) Staining intensity of SPINK6 protein was negative (0). (B) Staining intensity of SPINK6 protein was weak (1+). (C) Staining intensity of SPINK6 protein was moderate (2+). (D) Staining intensity of SPINK6 protein was strong (3+). (E) Comparison of high and low SPINK6 IHC Score groups in validation cohort. (F) KM survival curves of high and low SPINK6 IHC Score groups in validation cohort.