PDCD1LG2 and Autoimmunity: However, in the case of malignancies, the balance is disrupted as some tumors expressing PD-L1 and PD-L2 interact with PD-1, promoting T-cell exhaustion associated with reduced proliferation, cytokine secretion and survival of effector T-cells, but also enhancing the proliferation of Treg with the modulation of autoimmunity on the other hand [2].