CD4 and neoplasm: To determine the contribution of CD4+ and CD8+ T cell responses to the therapeutic benefit of OV-CXCR4-A treatment, we performed depletion studies by treating mice with anti-CD4 (clone YTS 191) or anti-CD8 (clone YTS 169.4) monoclonal antibodies (mAbs) by i.p. injection before and after tumor challenge Figure 4A).34