CDK4 and neoplasm: Next, flow cytometry was used to detect the cell cycle, and it was found that tumor cells accelerated the transition from G1 phase to S phase (Fig. 6D); Western blot showed that the expression of Cyclin D1, CDK4, and CDK6 protein was up-regulated, indicating that PHF19 upregulated the expression of Cyclin D1, CDK4, and CDK6 to promote the proliferation of SW480 and HT-29 (Fig. 6E).