SKP1 and cervical squamous intraepithelial neoplasia: Figure 4B shows there was a 3.4-fold increase in the frequency of cells harbouring ≥5 γH2AX foci (34%) following SKP1 silencing relative to siControl (10%), which is similar to that observed within the bleomycin treated (positive control) cells (40%). Collectively, these data show that SKP1 silencing induces replication stress and DSBs that are consistent with both CIN and chromothripsis [24,35,36].