Changes in VAF are significantly increased during treatment and clinical change as compared with stable disease. For any 2 consecutive aspirations in patient follow ups, their median ΔVAF was calculated from all identified somatic mutations. Bars depict mean and standard error of calculated median ΔVAFs, and are grouped according to the clinical status (eg, clinical change in WHO status, LEN treatment) during the period between the 2 aspirations. The total numbers of patients and data points contributing to each specific group are indicated at the bottom of each bar (patients/data points).