Proposed mechanism for PRCA-related thrombocytosis. (I) Proposed mechanism I: decreased erythropoiesis directs differentiation toward the megakaryocyte lineage. (II) Proposed mechanism II: increased EPO due to PRCA leads to synergistic signaling between EPO and TPO at bipotential MEP, stimulating TPO receptors and resulting in increased megakaryocyte formation. BFU, burst-forming unit; CFU, colony-forming unit; E, erythrocyte; Eo, eosinophil; GEMM, granulocyte-erythrocyte-monocyte-megakaryocyte; GM, granulocyte-monocyte; LT-HSC, long-term hematopoietic stem cell; MEG, megakaryocyte; MPP, multipotent progenitor, ST-HSC, short-term hematopoeitic stem cell. Figure created with BioRender.com.