https://en.wikipedia.org/wiki/Syncytin-1
QT:{{” Syncytin-1 also known as enverin is a protein found in humans and other primates that is encoded by the ERVW-1 gene (endogenous retrovirus group W envelope member 1). Syncytin-1 is a cell-cell fusion protein whose function is best characterized in placental development.[3][4] The placenta in turn aids in embryo attachment to the uterus and establishment of a nutrient supply. “}}