Even in the absence of AD, APOE4 carriers had a significantly higher proportion of intermediate cells than age- and sex-matched APOE3/3 individuals (5.98 ± 0.76% increase, p < 0.0001; Figure 2G), supporting an APOE4-driven pericyte-to-myofibroblast transition. This evidence concerns the gene APOE and Alzheimer disease.