VISTA/PD-1H: a potential target for non-small cell lung cancer immunotherapy
The development of immunotherapeutic agents for oncology is based on the insight that tumor development and progression is highly dependent on the ability of tumor cells to avoid immune recognition and destruction. Numerous immunomodulatory alterations, enabling tumor cells to evade the immune system, have been described. However, on the basis of their mechanism of action, they can be broadly classified into three categories: (I) downregulation of molecules involved with appropriate antigen processing and presentation; (II) downregulation of immune activation pathways; and (III) upregulation of immunosuppressive pathways (1). Not surprisingly, many of the mechanisms that enable tumor cells to evade the immune system have also been implicated in the resistance to immunotherapies.