Discoidin domain (also known as F5/8 type C domain, or C2-like domain) is major protein domain of many blood coagulation factors. Blood coagulation factors V and VIII contain a C-terminal, twice repeated, domain of about 150 amino acids, which is often called "C2-like domain" (that is unrelated to the C2 domain). In the Dictyostelium discoideum (Slime mold) cell adhesion protein discoidin, a related domain, named discoidin I-like domain, DLD, or DS, has been found which shares a common C-terminal region of about 110 amino acids with the FA58C domain, but whose N-terminal 40 amino acids are much less conserved. Similar domains have been detected in other extracellular and membrane proteins. In coagulation factors V and VIII the repeated domains compose part of a larger functional domain whi