Complex sentence: The smoking cases are related to the nicotinic and acetylcholine receptor receives the nicotinic from the cigarettes, and stimulate the neurons, them affect the gene expression and it codes wrong and release the genes and increase the risk of lung cancer.
Split into simpler sentences: The smoking cases are related to the nicotinic and acetylcholine receptor receives the nicotinic from the cigarettes, and stimulates the neurons. These affect the gene expression when it codes wrong, it releases genes and increase the risk of lung cancer.