title: Invited commentary.
authors: University of Pennsylvania School of Medicine, 313 Stemmler Hall, 36th and Hamilton Walk, Philadelphia, PA 19104-4283, USA. gormanj@uphs.upenn.edu
authors: Joseph H
authors: JH
authors: Gorman
mesh_terms: D000818:Animals; D002815:Chordae Tendineae / Q000033:anatomy & histology*; D006801:Humans; D008943:Mitral Valve / Q000033:anatomy & histology*; D012756:Sheep; D013552:Swine