(A and B) IL-15 (10 ng/mL) induction of CB NK and LAK cytotoxicity against several tumor cell lines. Acute lymphoblastic leukemia cell lines: CCRF-CEM (T-lymphoblastoid cells) and CCRF-SB (B-lymphoblastoid cells); neuroblastoma cell lines: SK-N-MC and NB-100. (A) The tumoricidal spectrum of CB NK activity: IL-15 (10 ng/mL) v unstimulated: CCRF-CEM*, 229 ± 75 v 50 ± 34 LU; SK-N-MC**, 269 ± 91 v 18 ± 17 LU; NB-100**, 208 ± 25 v 22 ± 4 LU; n = 4. (▨) Medium; () IL-15 (10 ng/mL). (B) The tumoricidal spectrum of CB LAK activity: IL-15 (10 ng/mL) v unstimulated: CCRF-CEM**, 318 ± 3 v 55 ± 39 LU; CCRF-SB*, 436 ± 114 v 18 ± 12 LU; SK-N-MC**, 358 ± 13 v 50 ± 25 LU; NB-100**, 330 ± 40 v 33 ± 31 LU; n = 3. (▨) Medium; (▩) IL-15 (10 ng/mL). *P < .05; **P < .01.