However, reducing the levels of btl in Ras/Src-activated tumours (ras1G12V,btlRNAi;csk−/−) had minimal effect on primary tumour size or muscle wasting, indicating that tumour autonomous reduction of Bnl–Btl signalling was not responsible for the suppression of tumour growth in ras1G12V;csk−/−,bnlRNAi animals (Supplementary Fig. 3n–q). This evidence concerns the gene SRC and neoplasm.