(A) Sections from a control, proliferative phase (cycle day 10) endometrial biopsy stained with antibodies against Cx26, Cx43, non-immune serum (control) or hematoxylin and eosin (H&E). Horizontal magnification bar at right base of the H&E panel indicates 100 μm. (B) Anti-Cx43 antibody staining of proliferative (prolif., cycle day 11) and secretory phase (secret., cycle day 18) control and proliferative (prolif., cycle day 10) and secretory phase (secret., cycle day 20) eutopic endometrium from endometriosis (endo.) cases. Horizontal magnification bar at right base of the secretory endometriosis panel indicates 100 μm. (C) Endometrial biopsies from the same subjects as in (B) immunostained using anti-Cx26 antibodies. Horizontal magnification bar at right base of the secretory endometriosis panel indicates 100 μm.