Since caffeine and selective A2A antagonists induce the reinforcement and sensitization behaviors, and exhibit the therapeutic effects in animal models of PD, which are mediated by mesolimic and nigrostrial dopaminergic pathways projected to the striatum, it is reasonable to hypothesize that caffeine and selective A2A antagonists can modulate the neuroadaptation of dopaminergic neurons in the striatum. Here, IGKV2D-29 is linked to Parkinson disease.