Pathologic features of RARS-T heterozygous for JAK2 V617F G/T mutation. (A) Bone marrow aspirate shows frequent ringed sideroblasts (Prussian blue stain, original magnification, × 100). (B, C) Bone marrow biopsies from different patients show hypercellularity with clustered megakaryocytes (H&E stain, original magnification × 40). (D) Bone marrow biopsy with increased stromal reticulin (2+/4+) (Gomori reticulum stain, original magnification, × 40). (Panels A, B, D: Table 3, Patient no. 5; Panel C: Table 3, Patient no. 3.)