PRF1 and neoplasm: In C57BL/6 mice, the difference in tumour incidence between wild-type and perforin-1-deficient mice drops from 0.8 with a dose of 25 μg 3-MCA to 0.2 with a dose of 100 μg 3-MCA, whereas in 129/SvEv mice the difference is stable at doses of 25 and 100 μg 3-MCA (0.26 and 0.29, respectively).