Protein arginine methyltransferase 7 is a protein that in humans is encoded by the PRMT7 gene. Arginine methylation is an apparently irreversible protein modification catalyzed by arginine methyltransferases, such as PMT7, using S-adenosylmethionine (AdoMet) as the methyl donor. Arginine methylation is implicated in signal transduction, RNA transport, and RNA splicing. May be involved in etoposide-induced cytotoxicity, a chemotherapeutic agent frequently used for testicular cancer and small-cell lung cancer that can cause cytotoxicity in the treatment of other cancers. Down-regulation confers increased sensitivity to the Top1 inhibitor camptothecin (CPT).