Knowing that oxidative stress is contributing to NPC, which contains multiple chromosome rearrangements; while oxidative stress also induces apoptotic DNA fragmentation and the apoptotic nuclease, CAD, has been implicated in chromosome rearrangements; thus, we hypothesise that, oxidative stress-induced CAD activation may result in chromosome rearrangement which partly contributes to NPC development. The gene discussed is CAD; the disease is nasopharyngeal carcinoma.