The downregulated genes included, as might be expected, those related to Parkinson's disease (PD) (Vps13d), dopaminergic neuron differentiation (Nr2f1), regulation of DA receptor expression (Klf16), DA transporter (DAT) trafficking (Vav2), but also those linked to β‐catenin signaling (Tnks), synaptic proteins (Plekha5), and stimulus–response habits (Abl2). The gene discussed is VAV2; the disease is Parkinson disease.