Perhaps more striking is that artificially constructed hemizygous knockouts of GTF2I are associated with heightened sociability in murine systems [32] and a large-scale naturally occurring hemizygous deletion on human chromosome 7, which includes GTF2I, causes Williams Beuren Syndrome (WS) [33], a neurodevelopmental disorder that is characterized by cranio-facial defects and extremely high levels of social behaviors [34, 35]. Here, GTF2I is linked to Williams syndrome.