Pharmacological agents: antacids, antiepileptics, antiemetics (5-HT3 antagonists), antihypertensives, antiparkinsonians, anticholinergics, antidepressants, antitussives, antidiarrheals (by causing dehydration), cancer chemotherapy agents, diuretics (by causing dehydration), iron (orally administered), opioid analgesics, neuroleptics. This evidence concerns the gene HTR3A and cancer.