von Willebrand factor A domain-containing protein 2, also known as A domain-containing protein similar to matrilin and collagen (AMACO) is a member of the von Willebrand factor A-like (VWA) domain containing protein superfamily and consists of three VWA-like domains, two EGF-like domains, a cysteine-rich domain and a unique C-terminal domain. AMACO is an extracellular matrix protein and mostly deposited adjacent to basement membranes.

Expression is generally absent in normal colon and other normal body tissues, but it is induced an average of 78-fold in Stage II, III, and IV colon cancers, as well as in colon adenomas and colon cancer cell lines. it was found markedly induced in colon cancers  and may be useful diagnostic serum marker.