PTEN and non-small cell lung carcinoma: The study noted that in non-small cell lung cancer (NSCLC), aberrant activation of the PI3K-AKT-mTOR pathway is closely associated with resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), and that its activation is mainly caused by PIK3CA, AKT1 mutations and PTEN deletion.