Validation of discovered FL subgroups in a separate cohort. (A-B) Distribution of samples between cFL and dFL for every sample. (C) Forest plot of mutations with differential frequency between cFL and dFL in the validation cohort. (D) Mutation burden at aSHM target sites across tumors in the validation cohort. The star indicates significant differences compared with dFL. (E) Immunohostochemistry results for FOXP1 and KI67 staining in the validation cohort. The star indicates significant differences compared with dFL. (F) The Kaplan-Meier curve showing the TTT (years) between cFL and dFL tumors in the validation cohort.