PIK3CA and non-small cell lung carcinoma: A study using quantitative proteomics to analyze the effects of the EGFR inhibitor erlotinib on non-small cell lung cancer (NSCLC) cell lines showed that the drug significantly downregulated the phosphorylation levels of several key proteins such as p-AKT and p-mTOR, which are involved in the PI3K/AKT/mTOR pathway.