Tumor samples were normalized to the average ΔCt of the liver tissue, and 7 genes were subsequently observed to be downregulated in CRLM: CLOCK (median = 0.46, Q1–Q3 = 0.22–0.75, p = 0.006), BMAL1 (median = 0.21, Q1–Q3 = 0.14–0.36, p = 0.003), PER1 (median = 0.14, Q1–Q3 = 0.05–0.52, p = 0.003), PER2 (median = 0.63, Q1–Q3 = 0.25–0.86, p = 0.002), PER3 (median = 0.14, Q1–Q3 = 0.04–0.37, p < 0.001), CRY1 (median = 0.50, Q1–Q3 = 0.32–0.98, p = 0.002), and CRY2 (median = 0.31, Q1–Q3 = 0.09–0.61, p < 0.001). Here, PER1 is linked to neoplasm.