STAT5A and acute myeloid leukemia: Our study aimed to investigate the effect of bone marrow mesenchymal stem cell (BM-MSC) exosomes on AML and to explore whether these exosomes could regulate the expression of JAK2, STAT3, and STAT5 in HL-60 cells, which have not been widely reported elsewhere, as these proteins are known to play critical roles in leukemogenesis by regulating cell survival, proliferation, apoptosis, and drug response [4, 16].