JAK2 and myeloproliferative disorder: JAK2-V617F kinase activity induces a change from the inactive bent to the active open conformation of Very Late Antigen-4 (VLA-4, CD49d/CD29, and alpha4 beta1 integrin) and over-activates VLA4 and Lymphocyte Function-associated Antigen-1 (LFA-1, CD11a/CD18, and αLβ2 integrin) in myeloid cell lines and in granulocytes from MPN patients [22].