Bone Morphogenic Proteins Promote Cartilage Differentiation and Protect Engineered Cartilage From Fibroblast Invasion and Destruction. - Kaps,C.; Bramlage,C.; Smolian,H.; Haisch,A.; Ungethüm,U.; Burmester,G.R.; Sittinger,M.; Gross,G.; Häupl,T. (Arthritis Rheumatism, 2002)