iNOS expression and activity has been described by some in syncytiotrophoblast and placenta lysate.14,30,31 iNOS differences between normal and hypertensive pregnancies have been reported,32,33 while other studies have reported the absence of iNOS in the syncytiotrophoblast34,35 and a debateable relationship between iNOS and preeclampsia.36 Nevertheless, we think eNOS is the principal isoform bound to STBMV and STBEX. The gene discussed is NOS3; the disease is preeclampsia.