CPNE8 (copine 8) is a calcium-dependent phospholipid-binding protein involved in calcium-mediated intracellular processes and cellular signaling pathways 1. The protein functions in focal adhesion regulation, as evidenced by its ability to promote cell proliferation, migration, and invasiveness through focal adhesion kinase (FAK)-dependent mechanisms 2. CPNE8 has been identified as a quantitative trait gene candidate for prion disease incubation time in mice, with upregulated mRNA expression observed at terminal disease stages 3. The gene shows disease-relevant expression patterns across multiple conditions: it appears among proteins with increased observation frequency in Alzheimer's disease plasma 4, correlates with gastric cancer progression and poor prognosis 25, and represents a strong causal candidate for aortic distensibility and blood pressure regulation 6. Clinical significance includes its potential as a prognostic biomarker in gastric cancer, where higher expression correlates with tumor grade and TNM stage 5, and its association with immune cell infiltration patterns that may predict immunotherapy efficacy 2. The protein's diverse roles in calcium signaling, cell adhesion, and disease pathogenesis suggest it functions as an important regulatory component in cellular homeostasis and pathological processes.