To examine the functional interactions of p53 and Rnf8 in suppressing cancer; we first monitored cohorts of Rnf8−/−p53+/−, Rnf8−/−  ̧ p53+/− and WT mice for one and a half years for tumor development and Kaplan-Meier tumor free survival analysis was performed. This evidence concerns the gene RNF8 and cancer.