To assess the effects of sunitinib treatment on tumor cell p53 levels and transcriptional activity, 1 × 107 786-0 or A498 cells were implanted subcutaneously into the flanks of nude/beige mice and the resulting tumors allowed to grow to a diameter of 10 mm, at which point sunitinib treatment (50 mg/kg daily) was begun. This evidence concerns the gene TP53 and neoplasm.