Autoimmune side effects associated with different anti–CTLA-4 antibodies. Serum samples from mice that received anti–CTLA-4 treatment, as detailed in the Figure 2 legend, were collected on day 30 (A) and day 55 (B) and tested for anti-dsDNA antibodies. Data shown are means and standard deviations (SDs) of OD at 490. (C) Correlation between tumor growth suppression and anti-DNA antibodies in control IgG, L1B11, and K4G4, but not in L3D10-treated mice. Data shown are the means and SEM of tumor sizes and OD 490 of ELISA test using a 1:270 dilution of sera from tumor-bearing mice. Tumor size and anti-DNA antibody levels reflect data collected at 30 days after tumor challenge. The relative strength of anticancer immunity and autoimmunity has been repeated in 2 independent experiments involving 8 to 9 mice per group.