Cytokine productions in both PD-L1241-265 -specific CD4+ T-cell lines were significantly diminished against PD-L1-specific siRNA-transfected tumor cell lines compared with mock-transfected control tumor cell lines (Fig. 4c), suggesting that PD-L1241-265-specific CD4+ T-cell lines certainly recognize tumor cell lines expressing PD-L1. Here, CD4 is linked to neoplasm.