KIRREL3 and Alzheimer disease: However, since both genes are shown to be involved in differentiations of stem and progenitor cells, it is possible that the KIRREL3 rs4144611 TT or rs580382 CC, and EXOC6B rs61619102 CC genotypes (Figure 1B-D) rescue endothelial pathology in AD via promoting circulating CD34+CD133+ EPCs to differentiate into brain endothelia.