We used EVs derived from umbilical cord mesenchymal stem cells, modified with phospholipid‒polyethylene glycol‒N‐hydroxysuccinimide and conjugated with CD38 peptides (CD38‐EVs), to target myeloma cells that highly express CD38 antigen, and tested their safety and antitumour efficacy in mice with subcutaneous plasmacytoma, administrated via dissolvable transdermal MNs or intravenous injection. The gene discussed is CD38; the disease is plasmacytoma.