Even though there is no definitive research of A2B and A3 receptors in PD pathogenesis, in LPS-treated microglia, A2B receptors activation has been reported to aggravate pro-inflammatory factors production through phosphorylation of cAMP response element binding (CREB) and promoting the p38 mitogen-activated protein kinase (MAPK) pathway (Koscsó et al., 2012; Merighi et al., 2017). Here, CREB1 is linked to Parkinson disease.