Interestingly, in clinical samples, mutations in the PI3K/mTOR pathway do not appear to overlap with amplifications in the MYC family, another relatively common event in SCLC (~16% of cases) that has been reported in a human mammary epithelial cell (HMEC) model of acquired resistance to BEZ235, which targets PI3K and ATR [50]. This evidence concerns the gene ATR and small cell lung carcinoma.