To ascertain whether the observed decrease in proliferation in the 5TGM1-PTTG-kd cells corresponded with reduced tumour growth in vivo, the 5TGM1-PTTG-kd and 5TGM1-SCRAM cell lines were injected i.v. into C57BL/KaLwRij mice and tumour burden was monitored at weekly intervals by bioluminescent imaging. The gene discussed is PTTG1; the disease is neoplasm.