PRMT5 and cancer: PRMT5 has pleiotropic functions and exerts oncogenicity by different mechanisms in many cancers [6,7], by functioning as a writer of symmetric dimethylation of the histone 3 at arginine 2 (H3R2me2s), arginine 8 (H3R8me2s) and histone 4 arginine 3 (H4R3me2s) marks associated with epigenetic silencing, exemplified by PRMT5 maintenance of breast cancer stem cells by epigenetically regulating FOXP1 [8].