Sixteen studies addressed the role of activin A, inhibin A, or follistatin-related proteins in preeclampsia risk and prediction through the estimation of the odds ratio (OR) [21,28,31] and area under the curve (AUC) from a receiver operating characteristic (ROC) curve [16,17,18,19,20,23,25,29,34,37,38,39,41]. This evidence concerns the gene FST and preeclampsia.