The Useless Gene That Might Help Us Detect Cancer

A gene called ORF1, referred to as Line 1, is found in the human genome, but it has no purpose that we can find. Scientists have long considered it an example of junk DNA. But just because it does nothing to benefit our bodies' functions doesn't mean it doesn't do anything, as Hank Green of Sci Show explains. Line 1 is a cut and paste machine, replicating itself and inserting its copies into other strands of DNA. It's not too picky about where it inserts itself, either, which can be a problem. Line 1 can turn up in a place that breaks another gene sequence and cause chaos as the affected cells replicate, enabling many horrible syndromes including cancers. However, the fact that it replicates with growing cancers means that we may find a way to detect it in a blood test. Elevated levels of line 1 will not exactly diagnose cancer, since it won't show us the location of tumors, but it can turn out to be a screening test that sends affected people for more tests. This video is only 6:45; the rest is an ad.