We previously demonstrated that local external beam radiation therapy (RT) and intratumoral (IT) injection of the hu14.18-IL2 immunocytokine (IC), a fusion protein linking hu14.18 anti-GD2 mAb and IL2, achieves improved tumor control and survival in mice bearing B78 melanoma, which expresses GD2 [10, 11]. Here, IL2 is linked to melanoma.