After the tumour volume reached to 100 mm3, the mice were administered 5-FU (20 mg/kg) every 2 days; the observation of mice for 20 days indicated that the tumour volume of parental TE4, but not OE-TE4, was significantly suppressed by 5-FU treatment compared with controls (Fig. 6E,F), indicating that TRAF4 plays a role in tumour development when exposed to 5-FU, and that TRAF4 may be a critical target for overcoming chemotherapeutic resistance of CSCs. This evidence concerns the gene TRAF4 and neoplasm.