The significant rise in TGF-β1 level in preeclampsia cases associated with a significant decrease in Tregs again points toward the “exhaustion” of Tregs [41] and its unresponsiveness toward the stimulus provided by TGF-β1 and PD-1/PD-L1 pathway resulting in an immunological derangement in PE. This evidence concerns the gene TGFB1 and preeclampsia.