RNF168 and neoplasm: To examine whether inactivation of Rnf168 predisposes for tumor development, we monitored cohorts of Rnf168+/+ (n = 56) and Rnf168−/− (n = 52) mice for a period of 12 months; however, none of the monitored Rnf168−/− mice developed tumors during the 1 year period (Figure 8C).