DAP3 (death-associated protein 3) is a mitochondrial GTPase that functions as a component of the mitochondrial small ribosomal subunit, where it plays a critical role in translating mitochondrial mRNAs 1. The protein exhibits intrinsic GTPase activity 1 and is essential for mitochondrial homeostasis, as evidenced by early embryonic lethality in DAP3-deficient mice, with mutant embryos displaying abnormal mitochondrial morphology and reduced cytochrome c oxidase-I expression 2. DAP3 contributes to the extrinsic apoptotic pathway in response to interferon-gamma stimulation 32. In cancer progression, DAP3 promotes hepatocellular carcinoma by increasing mitochondrial respiration and complex I activity through regulation of MT-ND5 expression; phosphorylation at Ser185 by AKT mediates DAP3's mitochondrial function 4. Elevated DAP3 expression correlates with poor prognosis in hepatocellular carcinoma, pancreatic cancer, and colorectal cancer, with high expression associated with increased tumor size, enhanced cell proliferation, migration, and invasion 567. DAP3 also regulates radioresistance in lung adenocarcinoma by controlling G2/M cell cycle arrest through checkpoint kinase 1 signaling 8. DAP3 serves as an independent prognostic marker and potential therapeutic target for multiple malignancies.