Overexpression of Path (ras1G12V;csk−/−,path) or CG1139 (ras1G12V,CG1139;csk−/−) had a minor, yet insignificant effect on tumour growth in Ras/Src-activated cells on CD (Fig. 5a–c and Supplementary Fig. 6a). This evidence concerns the gene CSK and neoplasm.