CMG-2 is an anthrax toxin receptor (ATR) family protein that contains one von Willebrand factor type A domain. As a result of alternative splicing, at least four isoforms of secreted or type I membrane proteins exist. CMG-2 is widely expressed in human tissues. It binds selectively to collagen type IV and laminin and is also capable of binding the protective antigen (PA) of Bacillus anthracis in a divalent cation-dependent manner. Soluble CMG-2 is a potent antitoxin and may be used as a treatment for anthrax.