Development of the FL24Cx gene expression signature. (A) Heat map of 45-gene signature in training cohort with gene group designations and mapped to EFS24. (B) Kaplan-Meier curve of EFS in cross-validated training data (24 months marked with vertical line), stratified by FL24Cx, with low-risk calls represented by the solid blue line and high-risk calls represented by the dashed red line.