While AB and CB, respectively, activated transient or sustained canonical cKIT-signaling, PV showed a non-canonical signaling including increased mTOR and ERK1 and decreased DEPTOR.
These include: i) more pronounced expression of phosphoSTAT5 protein in patients with JAK2V617F mutation compared to patients with wild-type of JAK2 kinase ii) different expression pattern of pSTAT5 in the nucleus and the cytoplasm of megakaryocytes and other bone marrow cells; iii) approximately 5-fold higher expression level of STAT5a gene in PV in comparison to patients with PMF and approximately 2-fold higher than in ET patients; iv) different, intracellular expression patterns of ERK2 and ERK1/2 antigens allowed to distinguish each subtype of MPN.