GAD1 and small cell lung carcinoma: LGI1 = leucine-rich, glioma inactivated, CASPR2 = contactin-associated protein-like 2, NMDA-R = N-methyl-D-aspartate Receptor, GABA-Br = Gamma-amino butyric acid receptor, type B, mGluR5 = metabotropic glutamate receptor 5, AMPAR = α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, GAD = glutamic acid decarboxylase, CRMP5 = collapsin response-mediator protein-5, SCLC = small cell lung cancer