This region of similarity, comprising 8 conserved cysteines, is found in the N-terminal region of several membrane-associated and extracellular proteins [1]. Although formerly called MANSC (for motif at N terminus with seven cysteines) it has now been renamed by MANEC (motif at N terminus with eight cysteines) by Richard Mitter and Stephen Fitzgerald after the discovery of an eighth conserved cysteine. It is postulated that this domain may play a role in the formation of protein complexes involving various protease activators and inhibitors [1].

1: MANSC: a seven-cysteine-containing domain present in animal membrane and extracellular proteins. Guo J, Chen S, Huang C, Chen L, Studholme DJ, Zhao S, Yu L; Trends Biochem Sci 2004;29:172-174. PMID:15124631