IGHG3 and Burkitt lymphoma: Applying human anti-CD52 IgG1-CAMPATH and IgG3-CAMPATH to WIEN-133 (human Burkitt’s lymphoma) cells induced CDC at higher EC50 values as compared to the respective anti-CD20 antibodies, and IgG3-CAMPATH reached only 30% of the maximum lysis of IgG1-CAMPATH.