The diagnosis of POEMS syndrome is confirmed when both the polyneuropathy and monoclonal gammopathy are present in association with one of the other three major criteria (Castleman disease, sclerotic bone lesions and increased levels of VEGF), and one of the six minor criteria (organomegaly, endocrinopathy, extravascular volume overload, skin changes, papilloedema, thrombocytosis/polycythemia). Here, VEGFA is linked to polycythemia.