Study workflow diagnostic samples from nt-FL and st-FL samples were analyzed by large-scale MS-based proteomics to investigate protein expression differences between the 2 patient groups. In addition, for the transforming FL group, a paired high-grade sample from the time of HT was also analyzed. Subsequent statistical and bioinformatic analyses were performed to identify risk groups based on the respective protein expression profiles. Lastly, selected proteins were evaluated using targeted immunohistochemistry. LFQ, label-free quantification. Created with BioRender.com.