The diagnosis of POEMS requires polyradiculoneuropathy and monoclonal plasma proliferating as 2 mandatory criteria, at least 1 of the major criteria (Castleman disease, elevated vascular endothelial growth factor level, and sclerotic bone lesion), and at least 1 of the minor criteria (organomegaly, extravascular volume overload, endocrinopathy, skin changes, papilledema, and thrombocytosis/polycythemia). The gene discussed is VEGFA; the disease is optic papillitis.