CX3CL1 and polycystic ovary syndrome: Women with PCOS had significantly reduced fractalkine secretion in the follicular fluid than control (Ctl) individuals (0.577 ± 0.025 versus 0.664 ± 0.018 ng/mL, respectively; P < 0.01, n = 16 and n = 21, respectively; Fig. 1A).