Caesalpinia sappan induces cell death by increasing the expression of p 53 and p 21WAF1/CIP1 in head and neck cancer cells - Kim, E C; Hwang, Y S; Lee, H J; Lee, S K; Park, M H; Jeon, B H; Jeon, C D; Lee, S K; Yu, H H; You, Y O (Am J Chin Med, 2005)