(a)
(b)
Figure 2: Double immunofluorescence staining of ALDH1A1 and 8-nitroguanine in chronic nasopharyngitis and NPC tissues. The expression of 8-nitroguanine (green) and ALDH1A1 (red) was assessed by immunofluorescence staining. Nuclei were counterstained by DAPI (blue). Original magnification is 100x (a) and 200x (b). Scale bar represents 50 μm.