To monitor the longer-term effects of MDM2 inhibition/p53 upregulation on engrafted chronic phase CML LSC in a scenario where therapy is removed (mimicking TKI discontinuation), we performed serial analysis of human cells at the end of a 28-day cycle of NIL + /- IDASA treatment, and then again after a 28-day treatment-free period (cohort 3, Fig. 4a). Here, TP53 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.