This view is also consistent with that A2AR KO enhances goal-directed behavior in instrumental conditioning (Yu et al., 2009) and strategy shifting in water maze paradigm (Wei et al., 2011), and is supported by the finding that caffeine (a non-specific antagonist of A2AR) treatment significantly improves attention and cognitive deficits in an attentional deficit and hyperactivity disorder (ADHD) animal model (Pandolfo et al., 2013). The gene discussed is ADORA2A; the disease is attention deficit-hyperactivity disorder.