Association of mutation load with response to rituximab therapy among FL patients. (A) The distribution of mutation load (per megabase) among untreated FL patients, grouped into mutation-high (>15 mutations/Mb, dashed line; n = 19), mutation-mid (≥6.6 mutations/Mb and ≤15 mutations/Mb; n = 85) and mutation-low (<6.6 mutations/Mb, dotted line; n = 112). (B) Kaplan-Meier estimates of PFS, stratified by treatment arm, are shown for the total biomarker-evaluated population. (C) Survival curves for patients with low, mid, and high mutation loads, stratified according to treatment arm. HRs, 95% CIs, and P values were calculated by using a Cox proportional hazards model, adjusted for age, FLIPI, sex, and response to induction therapy.