Kringle domains (kringle structures, triple loops) are triple-disulfide-linked domains that function as recognition modules for binding other proteins. Their presence is highly conserved among the blood clotting and fibrinolytic proteins. They were orginally named in 1975 by Magnussen et al when they were compared to the structure of certain Danish pastries. Apolipoprotein(a) contains 38 copies, the most so far described in man. Susceptibility to coronary artery disease has been linked to mutations of the Kringle domain in apolipoprotein(a) .