MDM4/MDM2 transcript levels in patients with MPN patients with +1q or 12q rearrangements. Gain of 1q in patients with MF is associated with increase in MDM4 transcript level. MDM4 and MDM2 transcript levels were measured in the mononuclear cells of patients with MPN with a gain of 1q, patients with MPN with a 12q rearrangement, and healthy donors. (A) There was a 1.64-fold increase in MDM4 transcript in patients with MPN, with gain of 1q (n = 9) as compared with healthy individuals (n = 10; P=.004), but not in patients with 12q rearrangements (n = 5). (B) There was no increase in MDM2 transcript in patients with MPN with 12q rearrangement (n = 5) or gain of 1q (n = 9) compared with healthy individuals (n = 5). MDM2, Mouse Double Minute homolog 2; MDM4, Mouse Double Minute homolog 4.