Lymph node response. The best response with respect to tumor size during idelalisib treatment. There were 40 patients in total, and 1 patient (white bar) did not have an evaluation for response. A total of 32 out of 39 patients (82%) had some decrease in measurable disease. Shown are on-treatment percent changes in the sum of greatest perpendicular dimension (SPD) of measured lymph nodes. The dotted line shows the percentage change that represents the criterion for lymphadenopathy response, according to Cheson et al,²⁰  where a indicates criterion for lymphadenopathy response.