For instance, in the recent study, Lee et al. revealed that single-nucleotide polymorphisms in six genes, including 3-hydroxybutyrate dehydrogenase, type 1 (BDH1), ST6 beta-galactosamide alpha-2,6-sialyltranferase 1 (ST6GAL1), RAB20, member RAS oncogene family (RAB20), PDS5 cohesin associated factor B (PDS5B), adenosine deaminase, RNA-specific, B2 (ADARB2), and SplA/ryanodine receptor domain and SOCS box containing 1 (SPSB1), were directly or indirectly related to conversion of mild cognitive impairment to AD [53]. This evidence concerns the gene RAB20 and Cognitive impairment.