When tumours arising from oncogenic Ras-transformed p53-/- and p53-/-Cry1-/-Cry2-/- cells are treated with OXA, p53−/− tumours continue to grow whereas p53-/-Cry1-/-Cry2-/- tumours exhibit extensive apoptosis and stop growing, corroborating the evidence that cryptochrome disruption in p53-/- cells makes them more sensitive to chemotherapy by OXA [42]. This evidence concerns the gene TP53 and neoplasm.