Prnp+/+ and Tga20 mice reached end-stage cancer more quickly (about 24 days) than did Prnp0/0 mice (about 31 days) suggesting that PrPC promoted invasion and metastasis of lung cancer; however, the amount of PrPC did not affect the time it took for mice to reach end-stage cancer. The gene discussed is PRNP; the disease is cancer.