In order to assess whether therapeutic tumor-targeting mAbs may drive memory NK cells expansion, we co-cultured healthy donor PBMC that displayed a sizeable population of memory (>3% of NK cells), with Raji lymphoblastoid B cell line, opsonized or not with rituximab anti-CD20 mAb, in the presence of IL-2 (Figure 2A). Here, IL2 is linked to neoplasm.