The neuroprotective mechanism of A2A antagonists is not fully understood, but our former study showed that A2A antagonists decreased free radical production and indicated that overactive glutamate neurotransmission might be the source of oxidative stress in the animal model of PD in which nigrostriatal neurons were damaged with 6-OHDA (Gołembiowska and Dziubina 2012). The gene discussed is IGKV2D-29; the disease is Parkinson disease.