Fig. 3

In situ hybridization of EBV-encoded small RNAs (EBERs) in nasopharyngeal tissue sections and brushing smears (40×). a Nasopharyngeal tissue from a nasopharyngitis patient shows no EBERs expression. b Nasopharyngeal tissue slice from a NPC patient shows strong signal of nuclear localization of EBERs within tumor cells. c Brushing smear sample from a healthy participant shows no EBERs signal. d Brushing smear sample from a NPC patient shows high EBERs expression in tumor cells