Threshold values were estimated from the ROC curve based on optimal sensitivity and specificity measured by the Youden Index.<h4>Results</h4>The study established a threshold value level for CD3+CD4+T-cells, CD4+CD25+T-regs, and CD4+FOXP3+ T-regs to separate individuals with preeclampsia from those without the condition. This evidence concerns the gene FOXP3 and preeclampsia.