There is encouraging evidence that CSF α-synuclein RT-QuIC performs similarly in the detection of primary Lewy Body pathology (8/8 positive) and Lewy Body co-pathology in AD, CJD, and primary age-related tauopathy (18/20 positive), with no significant difference in lag phase or peak ThT fluorescence, arguing for a role in the detection of co-pathology and against cross-seeding or inhibition by other aggregating proteins interfering with identification of α-synuclein pathology (Bongianni et al., 2019). This evidence concerns the gene SNCA and Creutzfeldt Jacob disease.