Thrombocythemia 3, also known as thrombocytosis 3, is related to essential thrombocythemia and lymphoblastic leukemia, acute, with lymphomatous features. An important gene associated with Thrombocythemia 3 is JAK2 (Janus Kinase 2). Affiliated tissues include bone marrow and bone, and related phenotypes are thrombocytosis and ischemic stroke