PTEN and cancer: To investigate whether ERK5 modulates autophagy in cancer cells, we used three cancer cell lines that show different oncogenic mutations: pancreatic ductal adenocarcinoma MiaPaCa-2 cells (containing mutated KRAS), endometrial adenocarcinoma Ishikawa cells (PTEN null), and cervical carcinoma HeLa cells (no alteration in Ras/Raf/ERK or PI3K-mTOR pathways).