CSK and neoplasm: Through genome-wide transcriptional profiling analysis of dissected tumour tissue from ras1G12V;csk−/− animals raised on CD and HSD (Supplementary Fig. 3a), we identified branchless (bnl), a Drosophila fibroblast growth factor (FGF) ligand as one of the most highly upregulated secreted factors in ras1G12V;csk−/− tumours in animals raised on an HSD (upregulated 5.0-log2fold) (Fig. 2a and Supplementary Fig. 3b).