For the APCS protein that differed between non-obese non-insulin resistant PCOS subjects and control women, correlations with age, BMI, insulin resistance (HOMA-IR), testosterone, C-reactive protein (CRP) and circulating levels of selected inflammatory proteins and protective heat shock proteins (HSPs) (interleukin 6 (IL6), tumor necrosis factor alpha (TNFa), heat shock protein 90 (HSP90AA1, HSP90) and heat shock protein family D protein 1 (HSPD1, HSP60) were determined. Here, IL6 is linked to polycystic ovary syndrome.