For DEGs that overlapped in longitudinal blood analyses of 3xTg-AD vs. wild-type B6129 vehicle (week 0–8; age, 4.5 to 6.5 mo) mice while opposite in direction of expression among groups (Supplementary Table 3), five ncRNAs (Gm13270, Gm17096, Gm42462, Gm5067, and Snora21), A830018L16Rik, Hhat1, Iqsec3, Limcd1, Masp1, Ppfia2, Slc13a4, and Spink10 appeared again as DEGs in cross-sectional analyses of 3xTg-AD mice vs. wild-type (6.5 mo; Supplementary Table 21). This evidence concerns the gene SNORA21 and Alzheimer disease.