CAP1 and metastatic colorectal cancer: These rather opposite results might be explained by the differences in the vaccination and chemotherapy protocols, e.g. high-dose vs. low-dose 5-FU, irinotecan vs. oxaliplatin, forgoing of gemcitabine, dosage and schedule of GM-CSF administration, or addition of CAP-1-peptide, in the time course of administration, in the patient cohort under study (metastatic colorectal cancer vs. unselected colorectal cancer), number of patients analyzed, and additional, yet unknown, confounding factors.