The role of neurogenic locus notch homolog protein 1 (NOTCH1)- and nuclear factor erythroid 2-related factor 2 (NRF2)-related pathways is highly heterogeneous in small cell lung cancer (SCLC) and, when they are both abnormally activated, they can synergistically cause neoplastic proliferation. The gene discussed is NOTCH1; the disease is small cell lung carcinoma.