CD4 and neoplasm: Assessment of tumor CD8+ and CD4+ T-cell percentages using flow cytometry revealed a trend toward a higher CD8+ T-cell percentage (Figure 4E), a significantly lower CD4+ T-cell percentages (P=0.0004, Figure 4F) and a higher CD8+:CD4+ T-cell ratio (P = 0.004, Figure 4G) in the combination arm than in the nivolumab-alone arm.