IGHG3 and AIDS: We previously developed a mouse/human chimeric IgG3 specific for TfR1 (ch128.1/IgG3) and showed that this antibody exhibits antitumor activity in an in vivo model of AIDS-NHL using NOD-SCID mice challenged intraperitoneally with 2F7 human Burkitt lymphoma (BL) cells that harbor the Epstein-Barr virus (EBV).