Assessing PP2A function. c-Myc is elevated at diagnosis in patients destined to progress into BC. Levels of c-Myc phosphorylation on serine 62 (A) and total c-Myc protein levels (B). Stratification by clinical outcome and abbreviations as for the previous figures. CCR, n = 10; No-CCR, n = 5; and BC, n = 5. (C) PIM1 is higher in the CD34⁺ cells from patients who will later progress into BC, confirming that PP2A function is inhibited. CCR, n = 3; No-CCR, n = 3; and BC, n = 3.