PTEN and neoplasm: However, when we evaluated the lung tissues in detail (Fig. 1F, b), we found that knockout of PTEN increased the hyperplasia of bronchial cells but inhibited the growth of alveolar cells in mice with EGFRL858R-induced lung cancer, implying a differential effect of PTEN on the tumor burden in bronchial and alveolar cells in mice with EGFRL858R-induced lung cancer.