TP53 and neoplasm: As such, survival of Trp53(+/−) mice show an intermediate survival to that Trp53(−/−) and Trp53(+/+) mice, and tumours that develop in Trp53(+/−) mice do not always display loss of the remaining WT allele (Berger et al. 2011; Venkatachalam et al. 1998).