CD8A and melanoma: This allowed for simultaneous blockade of checkpoint molecule, PD-L1, and stimulation of co-stimulatory molecule, 4-1BB, resulting in robust activation of tumor-infiltrating CD8+ T cells (increased CD107+ and IFNγ+ CD8+ T cells; p < 0.05), decreased average tumor size, and improved survival in preclinical models of melanoma and colon cancers.