Increase of mutant TP53 VAFs in HSPC of TP53-mutated MPN patients upon MDM2 inhibitor treatment. (A) Comparison of various TP53-mutations’ VAFs in CD34⁺ cells of MPN1 patient after 10 days with or without 20 nM of idasanutlin. (B) Comparison of all TP53-mutations’ VAFs in CD34⁺ cells of 8 different MPN patients after 10 days in presence or absence of idasanutlin 20 nM. (C) Mean plus or minus SD of VAFs for all TP53 mutants found in 8 MPN patients after 10 days in presence or absence of idasanutlin 20 nM or ruxolitinib 70 nM in 4 other MPN patients. A paired Student t test was used, **P < .01. ns, nonsignificant; SD, standard deviation.