( Gio.tto/Shutterstock) The turn of the 21st century was an exciting time in the history of genetics. The first sequencing of the human genome was completed in 2003 and it provided numerous insights to the scientific community and society in general. In 2000, during his final State of the Union Address, President Bill Clinton made a point of how all humans share 99.9 percent of our genome — it’s actually more like 99.7 percent. By honing in on the genetic variants, or mutations, that exist for certain genes in the human population, medical geneticists achieved a capability that would have looked like science fiction to physicians of the 1970s. Deciphering the genetics that underlay our existence has so far led to measurable success in gene therapy for certain conditions, but scientists are realizing that genes do not have the final say in what happens to a cell and its owner.