Among the 23 genes previous studies have shown their correlation with AD, we have: GFAP [41, 42], PDGFRβ [43–45], NFKBIA [46], TNFRSF1B [47], NOTCH1 [48], BCL6 [49], CSF1R [50], LEP [51], DCLRE1C [52], KCNJ10 [53], MAP2K1 [54], VIP [55], SNCA [56], ENO2 [57], SST [58], UCHL1 [59], HPRT1 [60], STAT4 [61], CD14 [62], ITGB2 [63], SPP1 [64], STX1A [65], and SYP [66]. The gene discussed is SNCA; the disease is Alzheimer disease.