We and others have shown that one of the mechanisms of growth regulation of small cell lung cancer (SCLC) cell lines and cultured pulmonary neuroendocrine cells (PNEC) is by the binding of agonists to a cell surface receptor of the neuronal nicotinic acetylcholine receptor family comprised of homomeric α7 subunits, which functions as an ion channel with high permeability for Ca2+ [1-8]. The gene discussed is IGKV2D-24; the disease is small cell lung carcinoma.