The best response with respect to tumor size during idelalisib treatment, according to assessment by an independent review committee, is shown for the 125 patients in the study. Among the 122 patients with measurable lesions both at baseline and after baseline, 110 patients (90%) had improvements in lymphadenopathy, as assessed by changes in the sums of the products of the perpendicular dimensions (SPD) of index lesions. The dashed line shows the percentage change that represents the criterion for lymphadenopathy response, according to Cheson et al.25 FL denotes follicular lymphoma, LPL/WM lymphoplasmacytic lymphoma with or without Waldenström's macro-globulinemia, MZL marginal-zone lymphoma, and SLL small lymphocytic lymphoma.