Responders to therapy with lenalidomide have significantly different plasma concentrations of angiogenic and inflammatory cytokines. Cross-sectional analysis of plasma angiogenic and inflammatory factors shows that patients who responded to lenalidomide therapy (PR + CR, ) have significantly lower plasma concentrations (mean ± SEM) of the angiogenic factor FGF-basic (A) and the inflammatory cytokine IL-6 (B) than patients who failed to respond to treatment (SD + NR; ▩). Plasma samples were taken at baseline and following 7 days and 28 days of lenalidomide therapy. Although a trend suggesting decreasing VEGF concentrations in responders was noted, no statistical difference in VEGF plasma concentration was observed between the SD + NR and the PR + CR groups (C). *P < .05 (A); P = .018 (B).