A further rationale for focusing on the ANS function in WS in an attempt to illuminate the underpinnings of its unusual social–emotional behavior comes from a recent study implicating the endogeneous dysregulation of prosocial neuropeptides, oxytocin (OT), and arginine vasopressin (AVP), in the social phenotype of WS (Dai et al., 2012). Here, AVP is linked to Werner syndrome.