CXCR4 and acute myeloid leukemia: Exo from AML cells contain mRNA that are important for AML prognosis (FLT3-ITD, NPM1), for treatment, (FLT3-ITD, IGF-IR, CXCR4), and for behavior of leukemic niche (IGF-IR, CXCR4, MMP4) [117].