PDCD1 and neoplasm: Curran et al. demonstrated in the same experimental model that treatment with anti-CTLA-4 or anti-PD-1 increased the CD8+ Teff/Treg ratio around 10-fold, that the effector/tumor-cell ratio was about 1–2/1000, and that only when both mAbs were combined with a cellular vaccine, cures were observed (8).