In addition to the inhibition of CRC cell proliferation, downregulation of KIF4A can lead to cell cycle arrest at G0/G1 phase (Fig. 4a) via the accumulation of p21 and p27 and the depletion of cyclin D1, cyclin E2, and Cdk2 at both the protein and mRNA levels (Fig. 5a, b), which are required for the G1 to S phase transition in cell cycle progression. This evidence concerns the gene CCND1 and colorectal carcinoma.