TGFB1 and graft versus host disease: Stem- and mesenchymal stromal cell-derived EVs have been shown to influence the immune system by modulating natural killer (NK) cells, dendritic cells (DC), monocytes/macrophages, microglia, T and B cells (Xie et al., 2020); indeed, MSC-derived EVs containing anti-inflammatory interleukin-10 (IL-10) and transforming growth factor beta 1 (TGF-β1) reduced the NK release of interferon gamma (INF-γ) and tumor necrosis factor alpha (TNF-α) release, thus alleviating the inflammatory response in a graft-versus-host disease model (Kordelas et al., 2014).