CD8A and neoplasm: In preclinical models, agonistic 4-1BB contributes to tumor regression by promoting survival and avoiding AICD of CD8+ T cells and more importantly in the context of this review; in models using OVA-expressing tumors, it has been demonstrated that a combination of agonistic 4-1BB antibody and transfer of OVA-specific CD8+ T cells significantly improves tumor control (125, 126).