this and the fact that tn shows amino acid sequence homologies to the carboxyterminal part of the asialo-glycoprotein receptor and a cartilage proteoglycan core protein as well a binding affinity to plasminogen points to tn as being part of a larger molecule , which possibly has been cleaved by proteolysis at the cellular site and then passed into the blood , where it polymerizes into a tetramer .
C0032140
plasminogen
C0597304
proteolysis