Antagonist G inhibits small cell lung cancer (SCLC) growth, acts as a neuropeptide receptor antagonist, stimulates c-jun-N-terminal kinase (JNK) activity and apoptosis in SCLC cells.H-Arg-D-Trp-N-Me-Phe-D-Trp-Leu-Met-NH2 or H-RwNmeFwLM-NH2