CD8A and neoplasm: Similarly, inhibition of Ataxia telangiectasia mutated (ATM) promotes the release of tumor mtDNA into the cytoplasm, activating the cGAS/STING signaling pathway-mediated type I interferon immune response, facilitating the infiltration of CD8 + T cells in the tumor microenvironment, and suppressing tumor resistance to PD-1 therapy [23].