TP53 and colorectal cancer: However, Zhang et al. (Zhang et al., 2019a) reported discrepant results that circ-ZNF609 is downregulated in colorectal cancer tissues and patient serum samples, and it also induced cell apoptosis via upregulating p53. To summarize, the specific role and regulating mechanism of circ-ZNF609 in colorectal cancer are still unclear, requiring further elucidation.