In situ hybridization for arginase, Tnfrsf9, and Tnni2 in the gravid d16.5 and d19.0 wild-type and Cox-1 KO mouse uteri. In situ hybridization was performed (n = 4) from each gravid time point. Shown are representative light-field images (left) and dark-field images (right) from gravid d16.5 and d19.0 uteri (25×). The slides were counterstained with hematoxylin and eosin. Areas of hybridization appear white, demonstrating deposition of silver granules.