CFTR and polycystic ovary syndrome: In addition, High mobility group box 1 (HMGB1), a small protein with cytokine activity (16), is increased in follicular fluid (FF) from ovaries of PCOS women (17) in relationship with decreased Cystic fibrosis transmembrane conductance regulator (CFTR) expression in granulosa cells (17), as previously described in Cystic Fibrosis (CF) (18, 19).