Immunohistochemistry and immunofluorescence analysis showed that CDC25C, H2AFX, NBN, XRCC5 and RAD1 had positive strong expression in NSCLC tumor tissues and negative weak staining in normal lung tissues (Figure 9B) and mainly distributed in nucleus and cytoplasm (Figure 9C). Here, XRCC5 is linked to non-small cell lung carcinoma.