Alternative splicing (AS) is a fundamental mechanism of gene expression regulation that extremely expands the coding potential of genomes and the cellular transcriptomic and proteomic diversity. This dynamic and finely-tuned machinery is particularly widespread in the nervous system and is critical for both neuronal development and functions. Alternative splicing defects, therefore, frequently underlie neurological disorders. In the first chapter of this book, the authors focus on Parkinsons disease (PD), the second most common neurodegenerative disorder worldwide. They provide a current overview on the impact of alternative splicing in PD by representing the multiple splicing transcripts produced from the major PD-linked genes and their regulation in PD states; review the studies describing global splicing expression changes revealed by whole-genome transcriptomic approaches; and summarise the current knowledge about the alternative splicing modulation in PD through non-coding RNAs (miRNA and lcnRNA) molecules. The following chapter reviews tau alternative splicing in Alzheimer's disease. Chapter three examines the role of splicing factors in cancer prognosis and treatment. The last chapter studies nonsense-mediated decay and human disease.