In vitro assays demonstrated potent antigen-specific cytotoxic activity against BCMA+/GPRC5D+ MM cell line (NCI-H929), showing an overwhelming advantage of the engineered CAR-NK cells, with approximately 90% tumor cell lysis compared to minimal activity observed in CB-NK cells (no detectable killing) and wild-type iPSC-derived NK cells (around 10% killing rate). Here, GPRC5D is linked to Miyoshi myopathy.