Dozens of ancient viruses are 'switched on' in healthy cells throughout our bodies

Traces of ancient viruses are littered throughout the human genome, embedded within the DNA's structure. Scientists already knew that some of these viral artifacts can "activate" in cancer cells and potentially contribute to the disease's progression — but now, a new study reveals that the viruses are active in dozens of healthy tissues, too. "This study is really one of the first looks at what is happening in normal tissue," Bendall said. "We all are expressing, in all of our tissues, in all our cells, some of these viral remnants, and I think this study is really important in showing that."