TGFB1 and neoplasm: Although the proportion of CD4+ cells, CD8+ cells, macrophages, DCs or MDSCs were not changed in EV-treated CMS5a tumours (Supplementary Fig. 5), the expression of CD140a and TGF-β was markedly decreased in association with the disappearance of MSC and CAF areas on day 3 after i.t. administration of DUC18 CD8 and BALB CD8 EVs (Figs. 1a−c).