In this study, a comprehensive bioinformatics analysis was used to identify the prognostic circadian clock gene signature in COAD, which included CRY2, NR1D1, and PER2. The lncRNA KCNQ1OT1/hsa-miRNA-32-5p/PER2/CRY2 regulatory axis was identified and might be of great significance in the occurrence and progression of COAD. The gene discussed is PER2; the disease is colon adenocarcinoma.