Role of CpG in mediating effective vaccination with a CpG-loaded whole tumor cell vaccine. At left (1), CpG loading of tumor cells is independent of TLR9, suggesting broad applicability of this strategy to many tumor types. In center (2), CpG-loaded tumor cells function to specifically and efficiently deliver CpG to APCs. This CpG has a stimulatory effect on the APCs, leading to (3, right) more efficient antigen presentation and, in turn, better stimulation of an antitumor T-cell response.