ARMCX2 is an X-linked armadillo repeat-containing protein that functions in mitochondrial regulation and cellular signaling. As a subfamily 2 member of the GPRASP/ARMCX family, ARMCX2 possesses a mitochondrial targeting transmembrane domain and works in complex with TRAK2 and MIRO proteins to regulate mitochondrial trafficking in axons, influencing mitochondrial size, division, and cell cycle dynamics 1. Beyond mitochondrial functions, ARMCX2 participates in broader cellular pathways implicated in protein-protein interactions, nuclear transport, and transcription activation 2. In cancer biology, ARMCX2 expression levels serve as a prognostic biomarker across multiple malignancies. Low ARMCX2 expression correlates with favorable overall survival in gastric carcinoma patients and is associated with WNT and NF-κB pathway involvement 2. In colon cancer, ARMCX2 is a component of angiogenesis-related gene signatures predictive of prognosis and treatment response 3. ARMCX2 promoter hypermethylation occurs in cisplatin-resistant ovarian cancer, with potential roles in chemoresistance 4. In fragile X syndrome patients, upregulated ARMCX2 expression correlates with altered tumor suppressor activity 5. Additionally, ARMCX2 appears in extracellular matrix remodeling during liver tissue repair 6.