Cells in the placenta have an unusual trick for activating gentle immune defenses and keeping them turned on when no infection is present. It involves crafting and deploying a fake virus.
https://www.wired.com/story/during-pregnancy-the-placenta-hacks-the-immune-system-to-protect-the-fetus/?utm_source=dlvr.it&utm_medium=blogger
https://www.wired.com/story/during-pregnancy-the-placenta-hacks-the-immune-system-to-protect-the-fetus/?utm_source=dlvr.it&utm_medium=blogger