REN and metabolic syndrome: Therefore, taking into consideration the fact that polycystic ovary syndrome (PCOS) is very commonly associated with the metabolic syndrome, obesity and insulin resistance, and that enhanced activity of the renin–angiotensin system (RAS) is observed in the metabolic syndrome, Moin ASM et al. suggest that PCOS may correlate with the circulating soluble NRP-1 (sNRP-1) level [24].