pThis book describes the development of novel protein-RNA-binding assays and their applications in a high-throughput manner for the identification of small-molecule modulators of protein-RNA interactions to treat cancer and COVID-19.p pModulating protein-RNA interactions with small molecules is expected to provide novel biological insights of the interrelation of diseases with the protein-RNA interactome. The modulations may also be exploited therapeutically. For these reasons, the development of a simple, reliable, and sensitive protein-RNA-binding assay is necessary for high-throughput screening to discover new effective chemical entities capable of acting on diverse protein-RNA interactions. This book discusses the discovery of small-molecule modulators targeting protein-RNA interactions that are potentially valuable to treat cancer and COVID-19 by constructing novel high-throughput screening methods. The results of this dissertation provide valuable insights into the regulation of