1) the Trp53wm/+ mice express normal levels of WT p53 and are not tumor prone; 2) mutant p53 is converted from WT at the endogenous locus closely mimicking the clinical situation; 3) mutant p53 is induced in the specific tissue/cell of interest, limiting tumor development to a single tissue; 4) the tumor microenvironment and immune system of the animals are p53 WT. The gene discussed is TP53; the disease is neoplasm.