Representative dots of flow cytometry showed that the frequencies of IFN-γ- and TNF-α-producing CD4+ T cells were approximately nine times higher in the WT1 peptide-stimulated TIIs than in the nonstimulated mice, showing the infiltration of WT1-specific CD4+ T cells into tumor in WT1 peptide vaccine-treated mice. Here, CD4 is linked to neoplasm.