GSK591 is a chemical probe of PRMT5 (protein arginine methyltransferase 5), which plays a key role in various biological processes. PRMT5 is related to many human diseases including certain cancers like mantle cell lymphoma (MCL). Therefore, GSK591 is a useful tool for testing biological and therapeutic hypotheses. Study has shown that it can potential inhibit the PRMT5/MEP50 complex and symmetric arginine methylation of SMD3.