Results of human in vitro angiogenesis assay by disease stage. Bar charts show the degree of tubule formation (total tubule length) with the human in vitro angiogenesis assay expressed as a percentage of NT control. Results demonstrate stimulation of angiogenesis by the bone marrow plasma of patients with newly diagnosed myeloma (A), MGUS (B), and SMM (C) with marked inhibition of angiogenesis by the bone marrow plasma of most patients with MGUS.