These data highlight that transfusion of exNK cells, exNK+PD1 blockage and exNK cells plus PD-L2 blocking on tumor cells are highly effective in suppressing tumor growth and improving survival of myeloma bearing mice, and exNK+PD1 blockage treatment appears to be most effective over the other two treatment approaches. This evidence concerns the gene PDCD1LG2 and plasma cell myeloma.