MYC mutant mice had a median survival of 31 weeks while the median survival of MYC/Rb mutant mice was 27 weeks; when the mice that did not die from liver cancer were excluded from the analysis, the median survival for MYC and MYC/Rb mutant mice decreased to 27 and 16.5 weeks, respectively, with a P value of 0.07 in a Gehan-Breslow-Wilcoxon test. This evidence concerns the gene RB1 and liver cancer.