The paraoxonases are multifaceted and pleiotropic enzymes encoded by three highly conserved genes located on chromosome 7q21.3�C22.1. They have multifunctional roles and are involved in various biochemical pathways. These include protection against oxidative damage and lipid peroxidation, modulation of endoplasmic reticulum stress, regulation of cell proliferation/ apoptosis contribution to innate immunity and detoxification of reactive molecules and bioactivation of drugs. Phylogenetic analysis has shown that PON1 and PON3 arose from gene duplication of the ancestral PON2 gene. PON1 and PON3 are circulating proteins associated with high-density lipoproteins whereas PON2 is expressed in many tissues and is cell associated. Research in the PON family has increased greatly in the last few years, particularly in the cardiovascular field. Nothing is known about the role of PON2 in the placenta or whether it plays a role in labour. However since PON2 plays a role in oxidative stress and inflammation, both BMS-770767 features of labour, we hypothesised that placental PON2 expression would alter during labour. Thus the aim of this study was to examine the spatial expression of PON2 in placentas obtained from women who delivered by cesarean section and were not in labour and to compare the expression of each zone with the equivalent zone of placentas obtained from women who delivered vaginally following an uncomplicated labour. Human term placentae were collected from pregnant women at the Southern General Hospital, Glasgow. All ethics protocols were followed as per Declaration of Helsinki. The study was approved by the West of Scotland research ethics service CKI-7 dihydrochloride Signed patient consent was obtained prior to delivery. Patients were handed an information sheet telling them about the study before being handed the consent sheet. The information and consent sheets were also approved by the ethics committee. All signed consent sheets were stored incase of the need for audit. The PON family form dimers and trimers and can be glycosylated; this may, in part, explain the range of different molecular weights reported to date. In the present study two main bands were detected with the PON2 antibody. The smaller band of around 43 kDa is the range reported for PON2. The larger band around 62 kDa has been described in liver lysates; reported in the PON2 antibody datasheet.