CXCL12 and myeloproliferative disorder: Additionally, leukemia cells could also stimulate MSCs to differentiate into OBCs to support LSC proliferation (Schepers et al., 2013), while MSCs may accelerate abnormal HSCs over-proliferation through secreting more SDF-1 in myeloproliferative neoplasm (MPN) patients (Arranz et al., 2014).