KRAS and cancer: Consistent with this proposal, in KrasLSL-G12D/+ mice, which harbour oncogenic Kras, pharmacological upregulation of Nrf2 by treatment with SFN after lung tumourigenesis had been initiated has been found to result in a modest 1.35-fold increase in the number of tumours observed on the surface of the lungs [106], though it should be noted that this is possibly controversial as prolonged treatment with SFN has also been reported not to increase cancer in Kras-based models of lung tumourigenesis [107].