Fig. 4.

TFPI is expressed in human placentation sites. (A) Schematic diagram of the structure of a human villous. (B) Two images showing localization of TFPI transcripts (red) to the EVT column and syncytiotrophoblast in the first-trimester human placenta. (C and D) Duplex in situ hybridization of TFPI (green) and HLA-G (red) in the first-trimester human placenta (C) and in first-trimester EVT cells associated with a uterine spiral arteriole (UA) (D). Note that TFPI is expressed in HLA-G–positive EVT cells, HLA-G–positive endovascular trophoblast cells, and syncytiotrophoblast cells. (Scale bar: 50 μm.)