CD4 and Alzheimer disease: In this cohort, FLG mutated AD patients did not exhibit a more severe disease phenotype than FLG wild‐type AD patients, in accordance with some studies but in contrast to others.27, 28 We first assessed the proportion of Tregs in the total lymphocyte population, because lymphocyte population size is more stable than CD4+T cell population size (Table S2, Figure 1A).