“…Two previous reviews in this journal presented the growing evidence that HERVs have made a significant contribution to human evolution, development and physiology, as well as playing possible roles in human diseases. 4,5 A reliable methodology for the assessment of virus-derived proteins in tissues and organs is important to our understanding of the role of HERVs in human evolution, physiology and disease. Our purpose was to study the expression of a single HERV, known as ERV3, and from this to derive a novel and reliable system for the detection of HERV-encoded proteins in human cells, tissues and organs.…”