High PD-L1/CD86 ratio on plasmacytoid dendritic cells correlates with elevated T-regulatory cells in liver transplant tolerance. Transplantation 2008;85(3):369-77.Tokita, D., G. V. Mazariegos, A. F. Zahorchak, N. Chien, M. Abe, G. Raimondi, and A. W. Thomso...