CALR and essential thrombocythemia: Among patients with ET, those with CALR mutations (CALR+) showed lower hemoglobin (Hb) levels (P < 0.001), lower white blood cell (WBC) counts (P < 0.001), and higher platelet (PLT) counts (P = 0.003) than those with JAK2V617F mutation (JAK2V617F+) (Table 3).