In support of our finding that treatment with rHuIL-12 was associated with reduced severe thrombocytopenia and hemorrhage, we recently reported that hematopoietic stem cells, megakaryocytes and osteoblasts in the bone marrow express the IL-12 receptor β2 subunit (IL-12Rβ2)[11], which is primary subunit for IL-12 signaling[25]. The gene discussed is IL12RB2; the disease is Thrombocytopenia.