TP53 and in situ carcinoma: However, the low frequency of the p53 gene changes (19% CIN III/in situ carcinoma) in comparison with the high frequency of high-risk human papillomavirus infection (85.7% CIN III/in situ carcinoma) strengthens the view that p53 inactivation by human papillomavirus proteins plays a major role in the pathogenesis of cervical cancer.