Furthermore, the attachment of microtubules to the SPBs as well as the kinetochores may be controlled by Cdk1, and Cdk1 also regulates the assembly, positioning and elongation of the mitotic spindle; improper attachment of chromosomes to the spindle or aberrant spindle behavior can lead to CIN [335]. Here, CDK1 is linked to cervical squamous intraepithelial neoplasia.