Therefore, taking advantage of fusion proteins containing ligands for the HER2 extracellular domain [19], EVs were engineered to expose these moieties and gain preferential distribution to HER2-positive tumor cells in vitro and in vivo, indeed serving as new tools for selective tumor imaging [20], delivering cytotoxic drugs [21, 22], or co-activating immune cells to suppress tumor growth [23–25]. Here, ERBB2 is linked to neoplasm.