On the other hand, diagnosing LCNEC can be challenging due to its histological similarities with non-small-cell lung cancer (NSCLC) and, in some cases, small-cell lung cancer (SCLC) (as evidenced by the PI3K/Akt/mTOR pathway and other gene alterations) (Table S1). This evidence concerns the gene MTOR and large cell neuroendocrine carcinoma.