qRT-PCR validation confirmed the RNA-Seq results of nine DEGs; AKAP6 (AD vs MCI), VDR, MMP2, AKR1C2, ANGPT1, WISP1, ADAM12, KRT19 and SORCS2 and showed the same trend with the remaining DEGs; PLXNA4, PRLR, SEMA6D and AKAP6 (AD vs HC) (Figure 3). The gene discussed is KRT19; the disease is Alzheimer disease.