For example, guidance receptors such as Robo1/2 and ErBb4 have been linked to neurodevelopmental disorders, such as Autism Spectrum Disorder for Robo1/2 (Anitha et al., 2008) and schizophrenia and bipolar disorder for ErbB4 (Iwakura and Nawa, 2013; Mei and Nave, 2014). Here, ROBO1 is linked to bipolar disorder.