CPNE1 (copine 1) is a calcium-dependent phospholipid-binding protein that functions as a key regulator in multiple cellular processes with significant clinical implications. The protein primarily mediates calcium-dependent intracellular signaling and membrane trafficking, while also playing crucial roles in neuronal differentiation through AKT-dependent pathways 1. CPNE1 is involved in TNF receptor signaling and NF-κB pathway regulation, where it induces endoprotease processing of NF-κB subunits. In cancer biology, CPNE1 demonstrates oncogenic properties across multiple tumor types. It is overexpressed in gastric cancer, osteosarcoma, cervical squamous cell carcinoma, and ovarian cancer, where high expression correlates with poor prognosis 2345. The protein promotes tumor cell proliferation, invasion, and migration through activation of MAPK signaling pathways and regulation of proteins associated with tumorigenesis 23. Additionally, CPNE1 influences the tumor microenvironment by promoting M2 macrophage polarization in ovarian cancer, contributing to immune evasion 5. Therapeutically, CPNE1 represents a promising target, as its silencing inhibits cancer cell growth and enhances chemosensitivity 3. The protein's regulation involves interactions with binding partners like HAX1, which can inhibit CPNE1-mediated neuronal differentiation 1.