IL2 and neoplasm: We first showed that established B78 GD2-expressing melanomas were not responsive to immune checkpoint inhibition, but showed potent curative responses, with tumor-specific T-cell memory, when treated with a subtherapeutic dose (12 Gy) of local radiation therapy (RT) added to intratumoral anti-GD2 immunocytokine (a fusion protein of anti GD2 mAb and IL2) and anti-CTLA-4 [11,12].