Abstract
In this issue of JEM, Thomas et al. (https://doi.org/10.1084/jem.20200891) provide elegant technological and conceptual advances that further our understanding of the immune cells enriched at the maternal-fetal interface. Using new isolation strategies to better separate maternal- and fetal-derived cells, the authors identify previously undefined maternal-derived immune cells associated with the fetal-derived placenta and provide an in-depth analysis of the markers and characteristics of placental Hofbauer cells.