PRMT5-IN-19 (Compound 41) is an selective orally active non-nucleoside PRMT5 inhibitor with IC 50 values of 23.9 nM (radioactive biochemical assay) and 47 nM (AlphaLISA assay). PRMT5-IN-19 can occupy the SAM-binding pocket in PRMT5 and block methyltransferase activity, which displays good selectivity over other PRMTs and PKMTs. PRMT5-IN-19 inhibits cell proliferation by inducing cell apoptosis , and can be used for cancer-related research.