CD4 and polycystic ovary syndrome: Emerging evidence, in fact, points to a Th17/Treg imbalance in PCOS, with a bias toward pro-inflammatory Th1/Th17 activity and reduced anti-inflammatory Treg function (36, 48)—for instance, peripheral CD4+CD25+FoxP3+ Tregs have been found to be significantly lower in PCOS women than in controls, while Th17 cells and IL-17 levels are elevated (36).