ARMC8 is a component of the CTLH E3 ubiquitin-protein ligase complex that mediates proteasomal degradation of target proteins including the transcription factor HBP1 1. The protein is evolutionarily conserved and localizes to cellular membranes, cytoplasm, and nucleus, where it interacts with cell-cell adhesion components including δ-catenins and αE-catenin 2. Functionally, ARMC8 regulates AMPK activity as part of the GID complex, with ARMC8 depletion increasing autophagy and extending lifespan in model organisms 1. Clinically, ARMC8 is significantly upregulated across multiple cancer types and serves as an independent prognostic biomarker. In colon cancer, elevated ARMC8 correlates with TNM stage, lymph node metastasis, and poor prognosis 3. Similarly, in ovarian cancer, high ARMC8 expression associates with advanced FIGO stage, histologic grade, and metastasis 4. In osteosarcoma, ARMC8 knockdown inhibits cell proliferation, epithelial-mesenchymal transition, and tumor growth in vivo 5. Mechanistically, ARMC8 promotes cancer cell invasiveness and migration by upregulating MMP7 and snail while downregulating adhesion molecules (p120ctn, α-catenin, E-cadherin) 34. Recent evidence indicates ARMC8 expression is regulated by the HDAC5/miR-142-5p axis in osteosarcoma 6. These findings position ARMC8 as a potential therapeutic target for multiple malignancies.