CTL assay and DTH used in monitoring cases of peptide-pulsed DC subcutaneous vaccination therapy (with high value of serum CEA by HLA2402) using CEA652 (9) that carried out at our facilities were verified. One out of 10 cases (10%) was SD, and 3 out of 10 cases were the induction of the CTL precursor observed for CTL assay in the peripheral blood of patients after the completion of 1 cycle (administered three times). In 2 cases, positive conversion was observed for DTH reaction. For the SD case, both CTL induction and positive conversion for DTH was observed. A reduction of the CEA value was observed in 3 patients among the 9 cases of PD. While the usefulness of CTL assay and DTH in monitoring cannot be determined solely by the verification at this time, the possibility of observing many clinical reactions could be shown for CEA652 (9) in cases where positive conversion was observed.