- Regenerating livers of old rats contain high levels of C/EBPalpha that correlate with altered expression of cell cycle associated proteins. Timchenko, N.A., Wilde, M., Kosai, K.I., Heydari, A., Bilyeu, T.A., Finegold, M.J., Mohamedali, K., Richardson, A., Darlington, G.J. Nucleic Acids Res. (1998)