Andrikovics et al. demonstrated that CALR mutations are found in about one-fourth of patients with ET or PMF and are associated with distinct clinical characteristics, and another study also found that CALR mutations are associated with younger age, more severe anemia, higher white blood cell (WBC) and platelet counts, lower Dynamic International Prognostic Scoring System Plus scores, and better survival compared to subjects with JAK2 mutations [17,18]. Here, CALR is linked to anemia (phenotype).