A, pRIP3, a central mediator of necroptosis, was not expressed at the implantation sites of Rb1d/d mice but was expressed at those of Rb1f/f mice at 1500h on day 5. Scale bar = 100μm; blue signal, nuclei stained by DAPI; purple signal, pRIP3; le, luminal epithelium; s, stroma; arrowhead, embryo; green dotted line, luminal epithelium; red dotted line, stroma. 