TGFB1 and acute myeloid leukemia: AML cells can also favor an immunosuppressive niche by directly promoting T regulatory cell (Treg) induction (Figure 2C) [131,132] or through diverse indirect mechanisms: secretion of soluble factors altering T-cell immune responses (i.e., IL-10, TGF-β) [133], the release of EVs with immunosuppressive functions [134,135] or exploitation of the activation of other immunosuppressive cells, i.e., MSCs, M-2 polarized macrophages [136], and myeloid-derived suppressor cells [137].