Long-term follow-up of response to PEG-IFN-α-2a. (A) Hematologic response in patients with PV or ET. (B) Dynamics of JAK2V617F mutant allele burden in patients with PV or ET over time. Black horizontal lines indicate median values; black bars represent minimum and maximum values; yellow rectangular boxes represent values included between the 25% and the 75% percentiles.