CD19 and neoplasm: SEM and KOPN8 cells treated with CD19‐293‐EVs with increased abundance of CD19‐targeting modules demonstrated a dose‐dependent increase in tumor cell killing capability (Figure 1j; Figure S11a, Supporting Information), CD19 depletion (Figure 1k; Figure S11b, Supporting Information), and EV uptake (Figure 1l; Figure S11c, Supporting Information).