Figure 2: The expression of SDF-1 and CXCR4 in chronic nasopharyngitis (inflammation) and NPC tissues. (a) The expression of SDF-1 was assessed by immunofluorescence staining (green). Nuclei were counterstained by DAPI (blue). The red dotted line is border between cancer nest and stromal area. HE staining of parallel sections. (b) Immunoperoxidase staining of CXCR4 protein (brown). Original magnification is 200x. Scale bar represents 50 μm. Ca: cancer cells.