NADPH-cytochrome P450 reductase <p>This group represents a NADPH--cytochrome P450 reductase. This enzyme is required for electron transfer from NADP to cytochrome P450 in microsomes. It can also provide electron transfer to heme oxygenase and cytochrome B5 [<cite idref="PUB00054029"/>, <cite idref="PUB00054030"/>].</p>