Alpha-2-macroglobulin (α2M) is a large molecular weight glycoprotein belonging to the serpin (protease inhibitor) superfamily, widely distributed in blood and various bodily fluids. By inhibiting the activity of a broad spectrum of proteases (such as trypsin, thrombin, etc.), it plays pivotal roles in inflammation modulation, tissue repair, and immune regulation. It serves as a critical molecule in maintaining protease homeostasis within the body.