<prompt> The most important investigation in the given case to diagnose if the condition is a neoplasm?JAK-2EPO levelPaO2Bone marrow aspiration and biopsy  <response>: Ans. a JAK-2The figure shows increased platelets in smear and increased megakaryocytes in bone marrow. To diagnose this as essential thrombocythemia neoplasm; JAK-2 mutation analysis should be done. 