CD38 and plasmacytoma: In plasmacytoma NOD/SCID mouse models, CD38‐EVs encapsulated within MNs (CD38‐EVsMNs) effectively targeted the tumour cells much more than the standard EVs encapsulated within MNs (EVsMNs) and CD38‐EVs intravenously administrated (CD38‐EVsi.v), with reduced distribution to the lungs and spleen.