PIK3CA and cervical squamous cell carcinoma: For these studies, we selected HeLa (cervical adenocarcinoma derived cell line with PIK3CA-WT), SiHa (cervical squamous cell carcinoma cell line with PIK3CA-WT) and CaSki cells (a cervical squamous cell carcinoma cell line that is heterozygous for PIK3CA-E545K, Supplementary Table S1).