In immunofluorescence-based studies, we found that cotreatment with O6BG and CDDP reduced the numbers of NPC cells with active HR signaling compared with CDDP treatment alone; in plasmid-based studies, MGMT suppression reduced the number of genomic products induced by the HR pathway (Fig. 5). The gene discussed is MGMT; the disease is nasopharyngeal carcinoma.