SPN and precursor B-cell acute lymphoblastic leukemia: Interestingly, ANGPTL2-containing SEVs significantly enhanced B-ALL development, as displayed by much higher leukemia cell frequencies in peripheral blood (Fig. 5a-b), much higher frequencies of immunophenotypic B220+CD43+ LICs (Fig. 5c) and reduced overall survival (Fig. 5d) compared to Ctrl SEVs.