UBE4B and Alzheimer disease: Relevant studies have also found that the expression level of miR-9-5p is significantly decreased in AD models, and the up-regulation of miR-9-5p can target the ubiquitination factor E4B (UBE4B) and stress-induced phosphoprotein 1 (STIP1) homology and U-box containing protein 1 (STUB1) to activate autophagy and promote the degradation of tau protein, thereby alleviating AD symptoms [78].