CD4 and systemic lupus erythematosus: Because all these CMPK2 inducers can regulate foam cell formation and atherosclerosis through different mechanisms, the data may also suggest that, when the immune response is activated in SLE patients, many factors may be potential contributors to the induction of CMPK2, that is, IFN-α might not be the only contributor critical for the CMPK2 induction observed in CD4+ T cells and CD14+ monocytes from SLE patients (Fig. 1).