The outcome of R-CHOP–treated patients with FL according to tumor-infiltrating MC content. (A) PFS of 98 R-CHOP–treated patients according to high (> median 1.5; n = 47) and low (≤ 1.5; n = 51) Leder stain–positive MC content. (B) PFS of 73 R-CHOP–treated patients according to high (> 6.6; n = 35) and low (≤ 6.6; n = 38) tryptase-positive MC content. (C) PFS after front-line R-CHOP according to high (n = 34) and low (n = 36) Leder stain–positive MC content. (D) PFS of patients treated with immunochemotherapy at relapse according to high (n = 13) and low (n = 15) Leder stain–positive MC content.