To this end, we generated a preclinical CLL mouse model (Eμ-TCL1)10 that harbors a functionally inactivating mutation in the p53 DNA-binding domain (R172H)11 that corresponds to one of the most common hot-spot mutations (R175H) observed in patients with CLL12, 13 Thus, this model represents an ideal in vivo platform in which to evaluate this subtype of high-risk CLL. This evidence concerns the gene TP53 and B-cell chronic lymphocytic leukemia.