Of the three RAF paralogs (A-, B- and CRAF), CRAF has been implicated as the most important for initiating KRAS-driven lung carcinoma (Blasco et al. 2011; Karreth et al. 2011), while it is dispensable for KRAS-driven oncogenesis of pancreatic cancer, indicating that the dependency of tumor growth on RAF family members is context-specific (Eser et al. 2013). This evidence concerns the gene RAF1 and lung carcinoma.