To investigate the localization of potentially pathogenic CD4+ T cells relative to the vasculature, CellTrace Violet+ (CTV+) polyclonal CD4+ T cells were transferred from infection-matched (day 7 post-infection) IL-10−/− donors, and injected with Tomato lectin, which stains glycoproteins localized to the vascular endothelium. The gene discussed is IL10; the disease is infection.