On the cover: Inhibition of TGF-β-Smad2 signaling in the late phase enhances proliferation of cardiac myocytes. α-MHC-EGFP ES cells were infected with an adenovirus expressing sTGF-β IIR at day 5, labeled with BrdUrd at day 8, and then sorted as EGFP (+) cardiac myocytes. BrdUrd staining revealed inhibition of TGF-β action resulted in a greater replicative potential in differentiated cardiac myocytes. See related article, page 78.