Finally, fibroblast activated protein alpha (FAP-alpha) is an important protein in early pregnancy, as it is involved in decidualization and tissue remolding during implantation.45 CMV has been shown to downregulate matrix metalloproteinases, which are important enzymes that trophoblasts use to invade the uterine wall.46 Thus, early CMV infection may decrease FAP-alpha resulting in intrauterine growth restriction or spontaneous abortion, as these outcomes are well established consequences of fetal infection. Here, FAP is linked to abortion.