CHRNA4 and neoplasm: In a mouse model where Lewis lung cancer cells were implanted subcutaneously into mice, which were then exposed to sidestream smoke (SHS) or clean room air and administered vehicle or mecamylamine (an inhibitor of nAChR); SHS significantly increased tumor size, weight, capillary density, VEGF, and MCP-1 levels, and circulating endothelial progenitor cells (EPC).