Further, patients with SLE with both low C3 and C4 levels demonstrated shorter disease duration, higher acute cutaneous lupus prevalence, nonscarring alopecia, and increased positivity rates for anti-DNA antibodies, antiphospholipid antibodies, and direct Coombs’ tests compared with those with low C3 or C4 levels. Here, C3 is linked to systemic lupus erythematosus.