UPF3B and neurodevelopmental disorder: Similarly, UPF3B inactivating mutations in humans are non‐lethal but cause intellectual disability (Tarpey et al, 2007; Laumonnier et al, 2010) and are associated with neurodevelopmental disorders such as autism spectrum disorders and schizophrenia (Addington et al, 2011; Lynch et al, 2012; Xu et al, 2013).