Hematologic parameters in patients with CALR-mutated ET, JAK2 (V617F)-mutated ET, and JAK2 (V617F)-mutated PV. Data are shown in a box plot depicting the upper and lower adjacent values (highest and lowest horizontal line, respectively), upper and lower quartile with median value (box), and outside values (dots). Of note, patients with JAK2 (V617F)-mutated ET had markedly lower serum Epo values than those of patients with CALR exon 9–mutated ET, despite the fact that the difference in median Hb levels was <1 g/dL.