C4A and lobular neoplasia: The current study showed a higher urinary BKV load in the LN group than in the non-LN group, suggesting a more seriously disturbed or suppressed immunity in patients with LN due to active renal flares, which was reflected by the lower serum C3 and C4 levels, higher number of patients with anti-dsDNA and a greater degree of proteinuria, increasing dose of steroids, and more potent immunosuppressant use (Table 1).