CDK1 and colorectal carcinoma: Figure 1B shows that neither exogenous nor endogenous p8 killed DLD-1 cells by inducing apoptosis. Therefore, we surmised that p8 suppresses CRC growth by inducing cell cycle arrest. We examined the expression level of factors related to the cell cycle and found that p8 inhibited the p53-p21-cyclin B1/Cdk1 pathway (Figure 4A). Furthermore, we used flow cytometry to confirm that p8 induced growth arrest at G2 (Figure 4B).