CGAS and neoplasm: Pharmacological inhibition of ATM (e.g., KU-55933) reduces mitochondrial transcription factor A (TFAM) expression in melanoma and breast cancer cells, promotes mtDNA leakage into the cytoplasm, activates the cGAS-STING signaling pathway and downstream cytokine production, and enhances lymphocyte infiltration into the TME, resulting in anti-tumor therapeutic effects (80).