Many different human endogenous retrovirus (HERV) families are expressed in normal placental tissue at high levels, suggesting that HERVs are functionally important in reproduction. This gene is part of an HERV provirus on human chromosome 19 that has inactivating mutations in the gag and pol genes. The gene's envelope protein is expressed in the human placenta but is truncated at its C-terminus. [provided by RefSeq, Oct 2015].