SSC5D (Soluble Scavenger with 5 Domains) is a secreted glycoprotein containing five scavenger receptor cysteine-rich (SRCR) domains and a heavily glycosylated mucin-like C-terminal region 1. As a pattern recognition receptor, SSC5D binds pathogen-associated molecular patterns (PAMPs) on bacterial and fungal cell walls, inducing microbial aggregation and suppressing PAMP-induced cytokine release without possessing direct bactericidal activity. SSC5D also binds extracellular matrix proteins including fibronectin and laminin, and interacts with various scavenger receptors 2. Expression is restricted primarily to monocytes/macrophages and T-lymphocytes, with particular enrichment in placenta 1. SSC5D has emerged as a significant biomarker in multiple disease contexts. Serum SSC5D levels are markedly elevated in heart failure patients and correlate with N-terminal pro-B-type natriuretic peptide levels and reduced ejection fraction, suggesting roles in cardiac fibrosis 3. In metabolic dysfunction-associated steatotic liver disease (MASLD), SSC5D is part of validated biomarker panels demonstrating high accuracy (AUC 0.82-0.89) for fibrosis staging and predicting fibrosis development 45. SSC5D is also incorporated into a 10-protein score predicting hepatic steatosis and cardiovascular-kidney-metabolic disease risk 6. Additionally, SSC5D levels are associated with per- and polyfluoroalkyl substance (PFAS) exposure and inflammatory/immunoregulatory pathways in adolescents 7, and elevated SSC5D predicts treatment response in advanced hepatocellular carcinoma 8.