<prompt> Answer this question truthfullyWhat is the cause of lung cancer?  <response>: <reason> The direct cause of lung cancer is DNA mutations that often result in either activation of proto-oncogenes e.g. K-RAS or the inactivation of tumors suppressor genes e.g. TP53 or both. The risk of these genetic mutations may be increased following exposure to environmental insults, which are regarded as risk factors that predispose to the development of lung cancer.To view a comprehensive list of risk factors that increase the risk of lung cancer, click here. 