IL21 and neuroblastoma: The researchers linked IL‐15 and IL‐21 to the anti‐GD2 antibody hu14.18 and found that the two‐novel antibody–cytokine conjugates, hu14.18‐IL15 and ‐IL21, were able to induce complete regression and prolong survival in NB tumor models, which had a stronger ADCC effect than hu14.18‐IL2 [23].