This may occur through the selection of cells that specifically recognize presented antigens from the infection or previous infections, or via a general activation of cytotoxic cells that recognize other antigens, including autoantigens, such as those derived from alpha-synuclein which are implicated in PD, Lewy Body dementias, multiple system atrophy, and multiple sclerosis125,126. The gene discussed is SNCA; the disease is Parkinson disease.