{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Alpha-1-antichymotrypsin glycoprotein, a member of the serpin superfamily, found in alpha (1)-globulin fraction in human serum. It inhibits chymotrypsin-like proteinases in vivo and has cytotoxic killer-cell activity in vitro. The protein also has a role as an acute-phase protein and is active in the control of immunologic and inflammatory processes, and as a tumor marker. Alpha-1-antichymotrypsin antibody reacts with histiocytes and histiocytic neoplasms. Its major application is defining the presence of alpha-1-antichymotrypsin in histiocytes and tumors derived from them."}]}]}