PYGO2 (pygopus family PHD finger 2) functions as a chr1 effector and transcriptional co-activator that facilitates Wnt/β-catenin signaling through epigenetic mechanisms. The protein directly binds to histone modifications, particularly H3K4me2/3, and associates with histone-modifying enzymatic complexes including MLL2 histone methyltransferase and GCN5/STAGA histone acetyltransferase complexes to enhance transcriptional activation 1. PYGO2 regulates histone gene expression and promotes H3K56 acetylation in mammary epithelial cells 2. The protein undergoes dynamic acetylation by CBP/p300 histone acetyltransferases, which promotes its nuclear-to-cytoplasmic translocation and recycling away from active transcription complexes 3. PYGO2 demonstrates significant clinical relevance across multiple cancer types, promoting malignant progression in colon cancer through BRPF1 activation 4, enhancing breast cancer stem-like cell expansion 1, and driving esophageal squamous cell carcinoma proliferation and migration 5. In prostate cancer, PYGO2 creates an immunosuppressive microenvironment by orchestrating p53/Sp1/Kit/Ido1 signaling, and its inhibition enhances immunotherapy responses 6. Additionally, PYGO2 expression correlates with liver fibrosis progression in hepatitis B patients, serving as a potential diagnostic biomarker 7.