On the cover: Histochemical analysis in the adult sheep aortic valve cusp using Movat's modified pentachrome stain demonstrates extracellular matrix organization and valvular interstitial cell compartmentalization. Movat's stain identifies collagen as yellow, proteoglycan as blue, elastin as black, muscle as red, and cells as purple. The arterial aspect or fibrosa of the cusp is oriented to the left. See related article, pages 1431–1438.