HACNS1 is located in an intron of the gene CENTG2 (also known as
Human Accelerated Region 2). HACNS1 is hypothesized to be a
gene enhancer "that may have contributed to the evolution of the uniquely opposable
human thumb, and possibly also modifications in the
ankle or
foot that allow humans to
walk on two legs". Evidence to date shows that of the 110,000 gene enhancer sequences identified in the human
genome, HACNS1 has undergone the most change during the
evolution of humans following the split with the ancestors of
chimpanzees. == References ==