MicroRNAs (miRNAs) are a class of non-coding RNAs, approximately 21-25 nucleotides in length, that regulate gene expression by complementarily pairing with the 3' untranslated region (3'UTR) of target mRNAs. The miRNA family is extensive, with each member targeting specific genes. They are widely present in the cell nucleus and cytoplasm, participating in biological processes such as development, cell differentiation, proliferation, apoptosis, and stress responses. The expression of miRNAs is tissue-specific, and disruptions in their expression or genetic mutations are associated with various diseases, including cancer, cardiovascular diseases, metabolic syndrome, and neurodegenerative diseases. Therefore, miRNAs serve as important biomarkers for disease diagnosis and treatment, as well as potential therapeutic targets.