CD28 and neoplasm: Consequently, we examined a new cell expansion formula, in which the three TLR agonists were combined with anti-CD3/CD28 antibody, interleukin 7 (IL-7), and interleukin 15 (IL-15), to amplify human blood-derived PD-1+CD8+ T cells, which represent a potential repertoire of tumor-reactive CD8+ T cells in cancer patients.