CD19 and neoplasm: To assess whether 67NR-primed CD19+ B cells retain their immunomodulatory properties in an immunocompetent host, opening the possibility of their immunotherapeutic role, we adoptively transferred CD19+ B cells from the BM of 67NR tumor–bearing donors into BALB/c mice orthotopically implanted with 4T1 tumor cells (Supplementary Fig. S2A).