Prognostic relevance of correct GE-classification in the validation cohort. Kaplan-Meier plots with log-rank P values for FFS (A,C) and OS (B,D) in patients with a GE profile for localized-stage FL (I/II) identified by the Lasso model (A-B) and Ridge regression (C-D) in the validation cohort of advanced-stage FL (III/IV) treated with R-CHOP. FFS (A) and OS (B) for patients with Lasso-based signature STS1 ≥ 13.672 (n = 202; 84 and 41 events for FFS and OS, respectively) and STS1 < 13.672 (n = 35; 12 and 3 events for FFS and OS, respectively). FFS (C) and OS (D) for patients with Ridge-based signature STS0 ≥ 2.932 (n = 201; 88 and 43 events for FFS and OS, respectively) and STS0 < 2.932 (n = 36; 8 and 1 event for FFS and OS, respectively). Thirty-seven patients with missing clinical follow-up were excluded.