Evolution of CALR mutant allele burden (%CALR) with time. Evolution of %CALR in each patient at different time points during treatment with peg-IFNα (A), aspirin only (B), or HU (C). Patients with CMR or PMR are depicted in red, and patients with no response or mMR are depicted in gray and black, respectively. Median %CALR before treatment and at the last time point during follow-up for patients treated with peg-IFNα (D), aspirin only (E), or HU (F). ASA, aspirin.