IGKV2D-29 and Parkinson disease: Kelsey et al. [14] found that caffeine and a selective adenosine A2A antagonist SCH58261, but not a selective adenosine A1 agonist N6-cyclopentyladenosine and a selective A2A antagonist 8-cyclopentyltheophylline, exhibited both monotherapeutic and adjunctive therapeutic effects in an established model of PD.