CFHR1 and systemic lupus erythematosus: Compared to this study, the frequency of FHR1 deficiency among SLE patients observed in our study is almost two times higher across different ethnic groups (Caucasian: 7.5% vs. 5.2%, African: 28.9% vs. 15.7%, and Asian: 2.7% vs. 1.1%), while we also we could not establish an association between the presence of FHR1 deficiency and disease severity or distinct disease manifestations (Table 4).