In situ hybridization analysis of PC, PS, CD39, PN1, TFPI, EPCR, 3-OST1, Par1, and Par4 in E9.5 mouse placenta. TGC indicates trophoblast giant cells; SP, spongiotrophoblast cell layer; and LB, labyrinth. TFPI, EPCR, 3-OST1, and PAR4 are expressed in TGC of E9.5 placenta. CD39 expression is observed in TGC and spongiotrophoblasts. PC is expressed in all 3 trophoblast layers. PS, PN1, and PAR1 are expressed in spongiotrophoblast cells. PAR1 expression extends to the labyrinth with staining in fetal blood cells. Bar represents 0.1 mm.