To determine whether the distinct TGF-β1 profiles seen in exosomes obtained from AML patients at diagnosis and during therapy are related to its biologic activity, purified normal human NK cells (Figure 5A) were co-incubated with AML exosomes isolated from the plasma of three different newly diagnosed AML patients selected based on different exosomal TGF-β1 expression patterns in western blots (Figure 5B). Here, TGFB1 is linked to acute myeloid leukemia.