Therefore, recognition of an absent or deficient CD4+ Th1 response may predict patients at risk for treatment failure and poor prognosis, but also correction of an inadequate CD4+ Th1 immune response with the use of anti-HER2 dendritic cell (DC) vaccines could consequently improve response to breast cancer therapy and be an important step in prevention of recurrence. The gene discussed is ERBB2; the disease is breast cancer.