Another paper that attempted to establish a timeline is that of Soldan et al [47], which used a composite score to evaluate 4 study groups of cognitively unimpaired patients, with the definitions of stage 0 (high Aβ and low tau), stage 1 (low Aβ and low tau), stage 2 (low Aβ and high tau), and suspected non-AD pathology (high Aβ and high tau). This evidence concerns the gene MAPT and Alzheimer disease.