In lung cancer, particularly non-small cell lung cancer (NSCLC), oncogenic alterations such as mutations in KRAS, EGFR, BRAF, and ALK rearrangements activate key signaling cascades, most notably the RAS–RAF–MEK–ERK and PI3K-AKT–mTOR pathways. The gene discussed is ALK; the disease is non-small cell lung carcinoma.