For instance, the effect of PLGA‐based aAPCs along with a checkpoint inhibitor (anti‐programmed cell death protein 1 (PD‐1) Ab) on TC activation and proliferation was investigated.[244] PLGA particles were fabricated and then the melanoma antigen‐loaded MHC‐IgG dimer (signal 1) and anti‐CD28 Ab (signal 2) were anchored on the surface of particles by EDC–NHS chemistry. The gene discussed is PDCD1; the disease is melanoma.