MKI67 and neoplasm: The percentage of Ki67 positive tumor cells did not change during treatment and was 86 ± 7, 92 ± 4, 90 ± 4, 89 ± 5, and 78 ± 4 %, for tumors at days −1, 1, 3, 7, and 14 post-5-FU treatment, respectively.