Experts from Stanford University recent research has discovered in human DNA is a special type of viruses which may be several million years. Ancient viruses, according to the results, protect the human embryo and regulates the activity of cells of the embryo.
HERVK belongs to the category of endogenous retroviruses. Scientists believe that the symbiosis of human DNA and virus more than 200 thousand years. HERVK synthesizes a protein that protects the embryo from getting into cells of another virus.
HERVK executes a protective function at the earliest stages of fetal development, when it is a set of several dozen cells. Representative viruses, protects fetus from other, more dangerous "brothers", for example, influenza.