TP53 and neoplasm: To investigate the impact of combined loss of ZMAT3, PUMA and p21 in TRP53-mediated tumour suppression we crossed Zmat3−/− with Puma−/−p21−/− mice to obtain Puma−/−Zmat3−/−, p21−/−Zmat3−/− and Puma−/−p21−/−Zmat3−/− animals (Fig. 1A).