TP53 and neoplasm: Based on the observations that p53wt/null and p53wt/mutant mice exhibit different patterns of tumor growth and metastasis, several groups proposed that mutant p53 can antagonize remaining wild-type p53, or that mutant forms of p53 can act as gain-of-function oncogenes that directly promote invasion, metastasis, and chemoresistance (Alexandrova et al. 2015, Boettcher et al. 2019).