In contrast, Col8a2 mutant knock-in mice carrying the Q455K and L450W mutations associated with early-onset FECD in human patients displayed corneal endothelial excrescences known as guttae, as well as the endothelial cell loss, which are hallmarks of human FECD (Meng et al., 2013; Jun et al., 2012). The gene discussed is COL8A2; the disease is Fuchs endothelial corneal dystrophy.