Our findings that levels of 4-hydroxynonenal (4HNE), a down-stream marker of oxidative stress, increased in p53-mutated resistant NB cells [23] suggest that generalized oxidative stress as characterized by increased levels of OH·, such as O2−·, lipid-hydroperoxide radical, mitochondrial membrane potential [42], glutathione levels, catalytic activities of antioxidant enzymes (superoxide-dismutase, catalase, glutathione-peroxidase, glutathione S-transferase) and membrane transporters (Ralbp1, P-glycoprotein, multidrug-resistance associated protein) should also be altered in p53-deficient cells. Here, RALBP1 is linked to neuroblastoma.