Cleavage of p21Cip1/Waf1 and p27Kip1 mediates apoptosis in endothelial cells through activation of Cdk2: role of a caspase cascade - Levkau,B.; Koyama,H.; Raines,E.W.; Clurman,B.E.; Herren,B.; Orth,K. (Mol Cell, 1998)