This, together with the finding of an increased capillary density, and increased expression of vascular endothelial growth factor (VEGF) and glial‐derived neurotrophic factor (GDNF), led to the hypothesis that STN‐DBS changes the microvasculature and causes sprouting of new more stables vessels compared to PD patients without DBS therapy (Pienaar et al, 2015). The gene discussed is VEGFA; the disease is Parkinson disease.