Although the role of Cks1 upstream of these kinases at the level of Ras GTPases and Raf kinases has not been investigated, squamous cell carcinomas and lung adenomas derived from RasH2 mice have been shown to exhibit fluctuations in levels of Cks1 when treated with genotoxic agents like 7,12-dimethylbenz[a]anthracene (DMBA), urethane and N-ethyl-N-nitrosourea (ENU) [91]. This evidence concerns the gene CKS1B and lung adenoma.