TP53 and cancer: To determine if the risk of malignant tumor development correlated with the brca2 genotype in tp53+/m zebrafish, the numbers of zebrafish that developed at least one malignant tumor were determined for brca2+/+;tp53+/m, brca2+/m;tp53+/m, and brca2 m/m;tp53+/m cohorts (Table 1).