CD4 and cancer: We conducted the screening test using PBMCs from 142 cancer patients to identify hTERT epitopes (Cytotherapy, accepted) and from approximately 200 cancer patients to determine WT-1 epitopes (manuscript in preparation) during the clinical trials and found one consistent pattern in the results—an inverse correlation between 4-1BB+CD8+ T cells and CD4+ T cells and/or 4-1BB+CD4+ T cells (Figure 1B).