Interestingly, the conjugation of RBCEVs with anti‐CD33 antibody increased the percentage of CellTrace‐positive leukaemia cells from 14%–18% in the controls to 42%–52% in the CD33‐targeting EV treatment in the bone marrow, and from 40%–49% in the controls to 71%–89% in the CD33‐targeting EV treatment in the liver (Figure 3C). Here, CD33 is linked to leukemia.