TP53 and cervical squamous intraepithelial neoplasia: Whilst these findings support TP53 mutations in some way causing or being permissive for CIN, we found no quantitative differences in ploidy between TP53-mutant and TP53-wild-type CIN+ tumours (data not shown), suggesting that an alternative (epi)mutation to TP53 inactivation may exist in the latter case.