Non-Coding RNAs in Molecular Pathology: Regulatory Networks and Disease Signatures

The vast non-coding transcriptome — encompassing microRNAs, long non-coding RNAs, circular RNAs, and small nucleolar RNAs — has emerged as a central layer of gene regulation with profound implications for human disease. This chapter reviews the biogenesis, molecular functions, and disease associations of major non-coding RNA classes, with particular attention to their roles in oncogenesis, cardiovascular pathology, and neurodegeneration. The potential of non-coding RNAs as diagnostic biomarkers and therapeutic targets is evaluated in light of recent clinical and translational evidence.