Expression of COX-2 in infolded layers and follicular liquid of Graafian follicles and cysts. (A) Low expression of COX-2 is seen in granulosa and theca layers in control group. (B) Due to high levels of angiogenesis, the density of follicular liquid, as well as COX-2 expression are high. The thick theca and granulosa layers indicate high expression levels of COX-2 in PCOS group. (C) A cyst is distinguishable, with no decrease in expression levels of COX-2 in HBV group. Arrows depict the predominant location of COX-2. Magnification 100 × .