Oligonucleotides modulate gene-specific expression within cells and can be used to identify genes involved in diseases. Continuing developments in oligonucleotide research have begun to unleash their potential as therapeutic agents. This volume focuses on small RNA-mediated gene silencing, micro RNA (miRNA), oligonucleotide chemistry and new technologies, delivery strategies, immunorecognition of nucleic acids, drug and therapeutic development, aptamers and other evolved systems, and preclinical models and clinical programs.