Exosomally transferred miRNAs alter leukemic phenotypes. A model depicting the different possibilities of exosomal miRNA transfer in the bone marrow, including (1) transfer from AML blast to normal hematopoietic cells (NHCs), (2) NHC to AML blast, (3) AML blast to AML blast, (4) bone marrow (BM) stromal cells to AML blast, (5) AML blast to BM stromal cells, (6) entrance of extramedullary produced exosomes into the hematopoietic niche, and (7) AML blast-derived exosomes leaving the BM and entering circulation.