CD4 and neoplasm: The differences observed in the CD137+ and CD137+PD1+ subsets could be ascribed to both CD8 and CD4 T cell populations (CD8+CD137+, R vs. NR 1.04 ± 0.67 vs. 0.59 ± 0.37, p = 0.0008; CD4+CD137+, R vs. NR 0.39 ± 0.3 vs. 0.22 ± 0.19, p = 0.005; CD8+CD137+PD1+, R vs. NR 0.73 ± 0.55 vs. 0.4 ± 0.3, p = 0.002; CD4+CD137+PD1+, R vs. NR 0.27 ± 0.2 vs. 0.12 ± 0.1, p = 0.0005) suggesting that each of this cell subset contribute to the overall anti-tumor immune response in this setting of patients.