In all tested SCLC cell lines, the activation status of PI3K/AKT/mTOR pathway is consistent with molecular genetic data, which shows that H446 cell line harbors the most alterations in the key genes of PI3K/AKT/mTOR pathway, and other cell lines harbor at least one alteration in the pathway (Table 1). This evidence concerns the gene PIK3CA and small cell lung carcinoma.