JAK2 and essential thrombocythemia: In the models of the MPN polycythemia vera (PV) and essential thrombocytosis (ET), HSP90 interacted with JAK2 and HSP90 inhibitor (PU-H71) could disrupted the stability of JAK2 protein and reduced lineage-specific myeloproliferation thus inhibited the cell growth in MPN patient samples (59).