FMO5 and systemic lupus erythematosus: Our class IV analysis also highlighted regulation of ROS metabolic processes, which has been reported as having a role in SLE.21CYBB, the gene that encodes the beta chain of cytochrome-245, a subunit of the NADPH oxidase enzyme complex, and the M2 macrophage marker CD163 were increased in all classes but most marked in class IV.