hsa-miR-181c-5p and hsa-miR-20a-5p were downregulated in AD patients and targeted both the transcription factors RORA that negatively regulated BDNF as well as MeCP2 whose upregulation further reduces the level of BDNF, thereby aggravating cognitive decline in AD patients (Fig. 5E). This evidence concerns the gene BDNF and Alzheimer disease.