PIK3CA and cervical squamous intraepithelial neoplasia: Consistent with the high level of CIN, genomic alterations occur with CDKI therapy, including loss of the RB gene, altered cyclin E1 expression [90], p27 inhibition [91], and activation of the Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA) pathway [92].