CS-BLI–based evaluation of antitumor activity of immune effector subsets. Healthy donor PBMCs were depleted of CD4⁺, CD8⁺, and CD56⁺ cells with the use of Miltenyi microbeads with LD columns (2 rounds of depletion). Cells were then cultured overnight in the presence of IL-2 (10 ng/mL). The next day luc⁺ MM.1S cells (5000/well) were plated at increasing effector-to-target ratios in the presence of IL-2 (10 ng/mL). luc⁺ MM.1S cell viability was measured 4 hours after the initiation of coculture. Cell viability was increased in fractions depleted of CD4⁺ (P < .0001), CD8⁺ (P < .0001), and CD56⁺ (P < .0001) cells; CD56 depletion had a more pronounced effect than CD4 or CD8 depletion (A). In addition, selection of CD56⁺ cells was compared with unselected PBMCs in the presence and absence of Len and Pom. Len (B; P = .0118) and Pom (C; P = .002) enhanced the antimyeloma cytotoxicity by CD56-enriched fractions (n = 4 for each condition). All experiments in this figure were conducted with PBMCs derived from the same donor, distinct from PBMCs for other figures.