MMP21 and coronary artery disorder: For example, Guimier et al. showed that direct mutagenesis of the mouse orthologue of MMP21 could recapitulate the left–right asymmetry defects (presenting as heterotaxy) and associated congenital heart defects (CHD) in F0 embryos, validating the discovery of this gene in multiple human CHD pedigrees (Guimier et al. 2015).