With the existing knowledge about PD-L1/PD-1 system and Tregs, this study was undertaken to find a link between sPD-L1 and Tregs in the serum in preeclampsia in order to assess the correlation between these two molecules and have an insight into the pathogenesis of preeclampsia from an immunological point of view. This evidence concerns the gene SPDL1 and preeclampsia.