PET analysis at 22 weeks post-infection revealed that Trf1Δ/ΔK-Ras+/G12Vp53−/− tumors showed less metabolic activity than Trf1+/+K-Ras+/G12Vp53−/− tumors indicating a lower grade of malignancy (Fig2F and G). The gene discussed is TERF1; the disease is infection.