From Tang WHW, Tong W, Shrestha K, et al. Differential effects of arginine methylation on diastolic dysfunction and disease progression in patients with chronic systolic heart failure. Eur. Heart J. 2008;29:2506–13; with permission. Abbreviations: NOS, nitric oxide synthase isoforms; ADMA, asymmetric dimethylarginine; SDMA, symmetric dimethylarginine; MMA, N-mono-methylarginine; DDAH, dimethylarginine dimethylaminohydrolase; PRMT, protein arginine methyltransferases; CAT, cationic amino acid transport