COL4A1 and spontaneous coronary artery dissection: Among the genes we prioritized in novel loci, a number encode proteins involved in extracellular matrix formation, including integrin alpha 1 (ITGA1), basement membrane constituent collagen type IV alpha 1 chain (COL4A1) and alpha 2 chain (COL4A2), serine protease HtrA serine peptidase 1 (HTRA1), metallopeptidase thrombospondin type 1 domain containing 4 (THSD4, encoding a partner of fibrillin 1, whose gene is located in a previously reported SCAD locus (FBN1)) and TIM metallopeptidase inhibitor 3 gene (TIMP3).