text: In 1993, Richard J. Roberts and Phillip Allen Sharp received the Nobel Prize in Physiology or Medicine for their discovery of "split genes". Using the model adenovirus in their research, they were able to discover splicing—the fact that pre-mRNA is processed into mRNA once introns were removed from the RNA segment. These two scientists discovered the existence of splice sites, thereby changing the face of genomics research. They also discovered that the splicing of the messenger RNA can occur in different ways, opening up the possibility for a mutation to occur.