CARM1 is an arginine methyltransferase which targets transcriptional coactivators, including SRC-1 and CBP, to regulate transcription at their cognate promoters. It has been shown to function as a coregulator for several members of the nuclear receptor superfamily. CARM1 is broadly expressed in a variety of tissues, with peaks of expression in the central nervous system (corpus striatum, olfactory bulb, hypothalamus, pituitary), reproductive system (ovary, testis) and metabolic tissues (muscle, thyroid, aorta). CARM1 has been shown to be overexpressed in prostate cancer and maps to a genomic location influencing circulating levels of homocysteine and therefore susceptibility to vascular diseases. Homozygous null deletion of CARM1 results in perinatal mortality and defects in protein methylation.