By contrast, there is conflicting data on the role of PD-L1 expression by T cells: On the one hand, Diskin and coworkers showed that T cell expression of PD-L1 maintained intra-tumor immune tolerance that resulted from the suppression of neighboring effector T cells via the PD-L1/PD-1 axis and the promotion of M2-macrophage polarization (30). The gene discussed is CD274; the disease is neoplasm.