Figure 1.
The PD-1/PD-L1 pathway in the peripheral system and at the maternal-fetal interface during pregnancy. If PD-1 is bound to PD-L1, there is no T-cell activation; thus, maternal immunotolerance towards the fetus is maintained. PD-1 = programmed cell death-1; PD-L1 = programmed cell death ligand-1.
