CD4 and polycystic ovary syndrome: Another study investigated the profiles of the type-1 T helper (Th1) (IFNg, IL-2) and Th2 (IL-4, IL-10) cytokines of CD3+CD4+ T lymphocyte subsets in follicular fluid (FF) and discovered that serum levels of IL-4 in patients with PCOS were reduced compared with those of controls (29).