Capturing spatial and dynamic heterogeneity in follicular lymphoma. Sampling of multiple nodal and extrandodal sites, to provide tissue for genomic, transcriptomic, proteomic, and functional assays on the malignant B-cell environment and TME, combined with PET-CT scans and circulating DNA, will provide a comprehensive biological profile. Sequential assays, performed at diagnosis and all subsequent clinical inflection time points, enable the temporal dynamics of site-to-site heterogeneity to be captured. Professional illustration by Patrick Lane, ScEYEnce Studios.