PTEN and squamous cell lung carcinoma: TCGA data also reveal that PTEN is downregulated in NSCLC tissues including lung adenocarcinoma (Additional file 2: Fig. S5d) and lung squamous cell carcinoma (Additional file 2: Fig. S5e) compared with that in normal lung tissues, and correlated with poor OS and post progression survival (PPS) of NSCLC patients (Fig. 7g).