Research into the paraoxonase (PON) gene family has flourished over the past few years. In the 1970s and 1980s, only PON1 was known, and the investigations were conducted, essentially, by toxicologists focusing on protection against organophosphate poisoning. Since then, two new members of the family, PON2 and PON3, have been identified, both being shown to play antioxidant and anti-inflammatory roles. Evidence exists indicating that the PON family is central to a wide variety of human illnesses such as cardiovascular disease, diabetes mellitus, metabolic syndrome, obesity, non-alcoholic steatohepatitis, and several mental disorders. However, research is hampered considerably by the methods currently available to measure the activity of these enzymes. In this review, we summarize the state of knowledge on PON biochemistry and function, the influence of genetic variations, and the involvement of PON in several diseases. The problems associated with PON measurement, such as sample acquisition, lack of reference methods, and variety of substrates, will be presented. Also, we cover some of the present lines of research and propose some others for future progress in this field.

Adaptive conflicts with the modern world: Mammals evolved in terrestrial environments. Those that now live in the marine environment have had to adapt to the particular selective pressures that this environment imposes. Meyeret al.surveyed the genomes of several marine mammal species to identify regions of convergent change. Multiple losses of theParaoxonase 1gene are evident in marine mammals, likely resulting from remodeling of lipid metabolism or antioxidant networks. The multiple occurrences of this loss of function across taxa indicate an evolutionary benefit. However,Paraoxonase 1is the primary mammalian defense against organophosphorus toxicity. Marine mammals may be at a great disadvantage in the Anthropocene if run-off of this agricultural product into the marine environment continues.Science, this issue p.591