CDKN1A and cancer: The levels of both phosphorylated and total p53 proteins, as well as p21Cip1/Waf1, were similarly increased in the CBG-treated SW480 and SW1116 cancer cells, indicating activation of the p53-p21Cip1/Waf1 axis (Fig. 4A), which could promote activation of the G1, S or G2/M checkpoints.