The evaluation of samples collected from cases of preeclampsia has shown increased corin and pro-ANP in the maternal circulation [27,28,29,30], reduced corin and increased pro-ANP in the uterus [27], and inconsistencies regarding corin levels in the placenta; one study showed increased placental expression and the secretion of corin protein [15], while another found no significant differences at the messenger (m)RNA level [31]. This evidence concerns the gene NPPA and preeclampsia.