According to these results, we evaluated the expression levels of CDKN1A, BAX and PUMA upon Nutlin-3 treatment in CLL cases with an unmutated TP53 status (TP53wt/wt or TP53del/wt genotype, overall accounting for 74 cases) versus cases with a mutated TP53 status (TP53mut/del or TP53mut/wt genotype, overall accounting for 26 cases), as defined by direct sequencing. The gene discussed is CDKN1A; the disease is B-cell chronic lymphocytic leukemia.