Figure 1.

Histopathological subtypes of nasopharyngeal carcinoma observed in the study (A‐C). A, Keratinizing squamous cell carcinoma. B, Non‐keratinizing carcinoma, differentiated type. C, Nonkeratinizing carcinoma, undifferentiated type. D, Negative control for HPV DNA in situ hybridization. A‐H, Magnification ×250. EBV, Epstein‐Barr virus; HPV, human papillomavirus; E, Immunohistochemical staining for p16. F, EBV RNA in situ hybridization (EBER). G, HPV E6/E7 mRNA in situ hybridization. H, HPV DNA in situ hybridization