<prompt> During cap stage signalling in the odontogenic epithelium is done by:Enamel knot.Enamel cord.Enamel septum.Enamel navel.  <response>: Recent studies have shown that enamel knot acts as a signaling center as many important growth factors are expressed by the cells of the enamel knot and thus they play an important part in determining the shape of the tooth. 