Promotion of oxygen generation in conjunction with metformin-mediated inhibition of oxygen consumption alleviated hypoxia in tumor tissues and enhanced the radiotherapeutic efficacy, while Mn2+ promoted IFN-γ secretion from NK cells via activating the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway 182. Here, CGAS is linked to neoplasm.