Chromosome 47

Gene tinkering run amuck.
Addition of a new chromosome to the human genome has the potential to cure disease, extend life, and augment both intellectual and muscular capabilities. Ruthless people don’t care about the crippling side effects, like memory loss and the immune system's virulent counterattack, and compete with each other for control of this revolutionary discovery, seeing only the dollar signs associated with its marketing. Killing their opponents and the lawmen standing in their way simply makes good business sense.