This study demonstrated that the mean Ki67 staining index in cancer tissue from patients with the highest quintile for serum folate (n=10; 117 ± 15nM) was 6.17 ± 3.2% versus 0.86 ± 0.92% for those in the lowest quintile (n=10; 18 ± 9nM, p< 0.0001) (52). This evidence concerns the gene MKI67 and cancer.