KIT and acute myeloid leukemia: After co-culturing for 48 h and detection of cell proliferation by CCK-8, we found that exosomes of AML cell line origin inhibited the growth of MDS cell lines, which we further verified with CD117, a protein closely related to proliferation, also known as c-kit [28], THP-1-exo inhibited the expression of CD117 in the SKM-1 cell line, while K562-exo did not affect the expression of CD117 in the SKM-1 cell line, probably because the co-culture time was not long enough to show any significant phenomenon.