Is there something called a k ras gene that causes lung cancer?

Yes: Kras is a gene involved in a pathway that controls cell growth. A mutationin the kras gene can lead to a propensity to develop lung cancer. There are several clinical trials that look at inhibitors in that pathway to treat patinets with advanced kras mutant lung cancer.

Yes: Mutation in the k-ras oncogene- which is the most common one found in lung cancer especially in adenocarcinoma- result in malignant transformation. Tumors with k-ras mutations tended to be smaller but more poorly differentiated, and they were associated with a significantly worse 3 year mortality rate .Attemps to overcome the impact of k-ras mutation in cancer is underway.