SNCA gene mutations are important in PD because the protein which this gene encodes, alpha-synuclein, is the main component of the Lewy bodies that accumulate in the brains of people with PD.[1] Alpha-synuclein activates ATM (ataxia telangiectasia mutated), a major DNA damage repair signaling kinase.[69] In addition, alpha-synuclein activates the non-homologous end joining DNA repair pathway. The aggregation of alpha-synuclein in Lewy bodies appears to be a link between reduced DNA repair and brain cell death in PD.[69]