PER3 single-nucleotide polymorphism (SNP) rs1012477 was first validated as a cancer susceptibility locus in a population-based case-control study of white men,15 with most of the replications reporting substantially different findings.16,17 As for 4/5-repeat, a majority of the individually published studies did not suggest a causative association with cancer.18–20 To assess the true association between the 2 PER3 SNPs and cancer susceptibility, we for the first time combined all different single studies and performed a comprehensive meta-analysis. The gene discussed is PER3; the disease is cancer.