ARMCX1 (armadillo repeat containing X-linked 1) is an X-linked gene that functions primarily as a tumor suppressor and regulator of cellular processes. In cancer contexts, ARMCX1 acts as a tumor suppressor by recruiting the E3 ubiquitin ligase FBXW7 to mediate c-Myc degradation, thereby inhibiting cell proliferation and metastasis in lung adenocarcinoma 1. Decreased ARMCX1 expression is associated with poor prognosis in gastric cancer, where it serves as an independent biomarker for diagnosis and prognosis 2 3. The protein is involved in mitochondrial function and cellular metabolism, particularly in skeletal muscle where it plays a role in mitochondrial damage response during delayed onset muscle soreness 4. ARMCX1 belongs to the GPRASP/ARMCX protein family, which contains armadillo-like repeats and includes a mitochondrial targeting transmembrane domain in subfamily 2 5. The gene has been identified as a hub gene in various disease contexts, including acute myocardial infarction where it is enriched in cell membrane signal transduction functions 6, and in prostate cancer progression involving epithelial-mesenchymal transition 7. Clinical significance includes its potential as a prognostic biomarker and therapeutic target in multiple cancer types.