Following up on this, Harold Varmus and J. Michael Bishop discovered the homologous SRC gene in normal human cells in 1976, for which they later received the Nobel Prize (pdf). (discovermagazine.com)
This image shows normal human cells (left) and genetically modified cells developed by the Salk scientists to simulate Werner syndrome (right), which showed signs of aging, including their larger size. (sciencedaily.com)
Over the past few years, researchers have discovered some of the important NER proteins by comparing normal human cells with those from people with a rare disease called xeroderma pigmentosum. (newscientist.com)