PGLYRP2 (peptidoglycan recognition protein 2) is a liver-specific pattern recognition receptor that functions as a key innate immune regulator with N-acetylmuramoyl-L-alanine amidase activity 1. The protein serves multiple functions including degradation of bacterial peptidoglycan into inactive fragments and antiviral immunity. PGLYRP2 demonstrates age-dependent hepatocyte-intrinsic immunity against hepatitis B virus through phase separation mechanisms, recognizing and eliminating viral DNA while suppressing capsid assembly 2. In inflammatory diseases, PGLYRP2 acts through the NOD2-NFκB pathway, where its N-terminal domain binds NOD2 on macrophages, activating inflammatory cascades that promote cytokine secretion 3. Clinical significance includes its role as a biomarker for various conditions: elevated serum levels correlate with coronary artery disease severity 3, systemic lupus erythematosus activity 4, and multidrug-resistant tuberculosis diagnosis 5. In hepatocellular carcinoma, PGLYRP2 downregulation through DNA methylation correlates with poor prognosis, while overexpression enhances antitumor immunity by promoting CCL5 chemokine production 6. Additionally, genetic polymorphisms in PGLYRP2 are associated with increased Parkinson's disease risk in certain populations 7.