VEGFA and polycythemia: In 2014, this was confirmed when both of the mandatory major criteria (polyneuropathy and monoclonal plasma cell proliferative disorder), one of the three other major criteria (Castleman disease, sclerotic bone lesions, and VEGF elevation), and one of the six minor criteria (organomegaly, extravascular volume overload, endocrinopathy, skin changes, papilledema, and thrombocytosis/polycythemia) were present [6].