ID 1.8.1.6 DE Cystine reductase. AN Cystine reductase (NADH). AN NADH-dependent cystine reductase. AN NADH:L-cystine oxidoreductase. CA 2 L-cysteine + NAD(+) = L-cystine + NADH. CC -!- Formerly EC 1.6.4.1. //