In this context we note that abnormality of the dopaminergic system has been confirmed to be one of the primary causes of GTS (Singer et al., 1982; Sandyk and Bamford, 1987; Ferré et al., 2009; Ferré et al., 2010; Filbey et al., 2010), both adenosine and endocannabinoids act as modulators of dopamine neurotransmission in the striatum (Müller et al., 2007) and it has been suggested that CB1 receptors form heteromers with dopamine D2 and adenosine A2A receptors (Ehlers et al., 2007). The gene discussed is ADORA2A; the disease is Tourette syndrome.