Fetuin-A, also known as alpha-2-Heremans-Schmid glycoprotein (AHSG), is a multifunctional plasma glycoprotein that plays a significant role in various physiological and pathological processes. It is primarily expressed in embryonic cells and adult hepatocytes, with lower expression levels in adipocytes and monocytes. Fetuin-A is involved in the regulation of calcium metabolism, osteogenesis, and insulin signaling pathways. It acts as an inhibitor of ectopic calcification, a protease inhibitor, an inflammatory mediator, an anti-inflammatory partner, an atherogenic factor, and an adipokine, among other roles. Research has also indicated that fetuin-A plays a key role in the pathogenesis of several diseases. For instance, it has been identified as a biomarker for neurodegenerative diseases and is associated with conditions such as vascular calcification, insulin resistance, and protease activity control. Furthermore, fetuin-A has been linked to keratinocyte migration and breast tumor cell proliferative signaling.