- Involvement of p21(WAF1/Cip1), p27(Kip1), and p18(INK4c) in troglitazone-induced cell-cycle arrest in human hepatoma cell lines. Koga, H., Sakisaka, S., Harada, M., Takagi, T., Hanada, S., Taniguchi, E., Kawaguchi, T., Sasatomi, K., Kimura, R., Hashimoto, O., Ueno, T., Yano, H., Kojiro, M., Sata, M. Hepatology (2001)