SNCA and Alzheimer disease: Out of the ADNI participants that had data available on alpha‐synuclein pathology, alpha‐synuclein pathology was detected in 41.7% of AD A+T− and in 40.9% of AD A+T+ but only in 15.2% of CU A−T− and in 18.3% of CU A+T+ groups (missing reported in Table S7).