CCDC85B (coiled-coil domain containing 85B) is a multifunctional nuclear protein that plays complex and context-dependent roles in cellular regulation. The protein functions as a p53-inducible regulator of β-catenin signaling, where it normally suppresses β-catenin activity through nuclear interaction with T-cell factor 4 and enhances β-catenin degradation independently of GSK3β 1. CCDC85B also interacts with p120-catenin family members at adherens junctions, particularly binding the head domain of p120-1A isoforms, suggesting roles in cadherin-mediated cell adhesion and neural development 2. However, CCDC85B exhibits paradoxical oncogenic functions in certain cancer contexts. In non-small cell lung cancer, cytoplasmic CCDC85B expression promotes cell proliferation and invasion through activation of AKT/GSK3β/β-catenin signaling pathways, correlating with advanced tumor stage and lymph node metastasis 3. The protein has been identified as a prognostic marker in colorectal cancer, where high expression associates with poor outcomes and influences glycosylation patterns in cancer-associated fibroblasts 4. Additionally, CCDC85B expression correlates with placebo responsivity in chr11 pain patients and serves as a biomarker for intracranial aneurysm instability 56. These findings suggest CCDC85B functions as a molecular switch whose cellular localization and context determine whether it acts as a tumor suppressor or oncogene.