TP53 and cervical cancer: In primary cervical tumours, which are HPV-negative, p53 mutations are very rare.35 Because the viral oncoprotein E6 binds to and inhibits the function of p53 protein, inhibition by HPV may be one cause of chemoresistance in cervical cancer.36 Mutated TP53 can also regulate the expression of chemo- and radioresistant genes, one of which includes MDR1.