First, Slitrk4 has been associated with neuropsychiatric disorders, as was the case for the other Slitrk family genes (Proenca et al., 2011); the results of this study show that Slitrk4 is a critical gene that suppresses fear-associated behaviors, raising the possibility of its involvement in PTSD or phobia-associated diseases. Here, SLITRK4 is linked to phobic disorder.