TP53 and B-cell chronic lymphocytic leukemia: Specifically, 4OH-tamoxifen-mediated activation of a Cd19CreERT2 allele in leukemic Eμ:TCL1;Cd19CreERT2;Trp53fl/fl animals19 led to a marked increase in leukemic burden within 12 weeks (Supplementary Fig. 3a) and a significantly earlier CLL-associated death of these animals, compared to their Trp53-proficient counterparts (Supplementary Fig. 3b).