Strikingly, reducing expression of path (ras1G12V,pathRNAi;csk−/−) or CG1139 (ras1G12V;csk−/−,CG1139RNAi) almost completely suppressed HSD-mediated Ras/Src-tumour growth (Fig. 4g, h and Supplementary Fig. 5b, c, g). Here, CHST3 is linked to neoplasm.