PIK3CA and cervical squamous intraepithelial neoplasia: CIN tumors are characterized with mutations in various tumor suppressor genes: APC (up to 85%), TP53 (40-50%), SMAD2/4 (10-20%), and DCC (5%), and proto-oncogenes: KRAS (30-50%), CTNNB1 (5-15%), and PIK3CA (20%) [4].