YM-254890 is primarily used in biochemical research to study G-protein signaling pathways. It specifically inhibits Gq proteins, making it a valuable tool for understanding the role of these proteins in cellular processes. Researchers utilize it to explore mechanisms in diseases where Gq signaling is dysregulated, such as cardiovascular disorders and certain cancers. Its application helps in developing targeted therapies by providing insights into Gq-mediated signaling cascades.