Here, we quantified immunoglobulin M (IgM) responses to various human tissues and the patient's tumor before and during adjuvanted chemotherapy (seven cycles of the FOLFIRI regimen (folinic acid/fluorouracil/irinotecan) plus cetuximab) of a patient with metastasized colon cancer. The gene discussed is CD40LG; the disease is malignant colon neoplasm.