CTLA4 and cancer: In recent years, the inhibition of critical pathways involved in T cell suppression, achieved by treatment with monoclonal antibodies against CTLA-4, PD-1 or PDL-1, the so called immune checkpoint inhibitors (ICIs), demonstrated a long-lasting response in several types of cancer and has become a standard of treatment for melanoma, non small-cell lung cancer (NSCLC), and Renal Cell Carcinoma (RCC) [24].