RAB38 and Alzheimer disease: Apart from protein coding GPCR family ADGRG7 and the Rab genes, RAB37 and RAB38, that are exclusively implicated in early AD, as mentioned earlier, we found several genes in vascular cell types that are significantly upregulated in early AD and are either not differentially expressed or slightly downregulated (statistically significant but with smaller log-fold change) in advanced AD.