4D N=4 Super Yang Mills in the planar limit has an infinite dimensional symmetry known as Yangian symmetry. Dualities respect symmetries, so what does this symmetry correspond to in the $AdS_5\times S^5$ string theory dual? If I remember correctly, in the boundary theory the infinite dimensional symmetry arises because the superconformal and the dual superconformal transformations do not commute but instead form the Yangian algebra. What is the analog in the dual? Do these extra symmetries that emerge in the planar limit have a nice geometric interpretation in the bulk?