To this purpose, [11C]-Donepezil PET was used in PD patients to measure significant AChE reduction in the small intestine of early PD patients, whereas [18F]-DA PET and [125I]-m-iodobenzylguanidine ([125I]-MIBG) scintigraphy were used to measure progressive heart denervation (Knudsen and Borghammer, 2018). The gene discussed is ACHE; the disease is Parkinson disease.