Optional larval anxiety models include recent transgenic models, e.g., (vesicular monoamine transporter 2 knockdown [125], a neurexin2aa deficiency [126], serpini 1 knockout [127], and brain-derived neurotropic factor loss [128]); however, there is no one known gene that causes anxiety [16], and, therefore, no one transgenic anxiety model. The gene discussed is SLC18A2; the disease is Anxiety.