OAS1 and systemic lupus erythematosus: Our results showed that cholesterol metabolism was upregulated in SLE and highly enriched in monocytes, which is the same as TNFSF13B and OAS1. According to previous studies, exogenous chemicals (xenobiotics), including many environmental exposures, consist of one of the risk factors for SLE (51), thus the xenobiotic metabolic dysfunction may also account for the pathogenesis of SLE.