E1A and Ras oncogenes are able to induce CIN [33] and in agreement, we detected the presence of tetraploid and near-tetraploid karyotypes (80 ± few chromosomes) in both E1A/Ras Hipk2+/+ and −/− MEFs. Here, HIPK2 is linked to cervical squamous intraepithelial neoplasia.