a, Survival curves of ATTAC mice dying of cancer (mice that had an overt tumour at time of death; mice with lymphomas, sarcomas and carcinomas were included, mice without tumours were censored). Median survival and percentage increase are indicated. b, Representative images of aged mice with and without senescent cell clearance. c, Spontaneous movement and exploratory behaviour of ATTAC mice analysed by the open field test. Error bars indicate s.e.m. *P < 0.05; **P < 0.01; ***P < 0.001 (log-rank test (a) and unpaired two-tailed t-test (c)).