[Immunotherapy and cancer: towards 2020.]

Immunotherapy is a novel treatment strategy that, even though implemented decades ago, has emerged with important clinical data in the last 10 years and is fulfilling the promise of prolonging survival in several types of cancer by restoring the immune system activity against the tumor. To understand its benefits it is necessary to correctly evaluate the right endpoints and to know and manage the toxicity profile. The two immune-checkpoint receptors that have been most actively studied in the context of clinical cancer immunotherapy are the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) and the programmed cell death protein-1 (PD-1), which are both inhibitory receptors and regulate immune responses at different levels and by different mechanisms. Despite the benefits shown by these checkpoint inhibitors in several types of cancer, there are still many patients who do not respond to immunotherapy. This is why research is focused on overcoming resistance and on how to identify molecular and mutational biomarker to fit the right therapy to the right patient.