Immunolocalization of SERPINE2 in the mouse uterus at different stages of the estrous cycle. Uterine sections during proestrus (A), estrus (B, C), metestrus (D), and diestrus stages (E) were incubated with anti-SERPINE2 antiserum or the antiserum pretreated with SERPINE2 protein (control) (C), and then treated with biotin-conjugated goat-anti-rabbit IgG and horseradish peroxidase-conjugated streptavidin (red). For contrast, specimens were further stained with hematoxylin (blue). Photographs were taken under bright-field illumination. Bar = 200 μm. cm, circular muscle; ge, glandular epithelium; le, luminal epithelium; lm, longitudinal muscle; s, stroma.