CTLA4 and neoplasm: Over the last decade, a more profound knowledge of the mutual interplay between tumor cells and the tumor microenvironment, a critical regulator of immune escape, has led to the development of immune checkpoint inhibitors (ICIs) that target CTLA-4 or PD-1 on exhausted CD8+ T-cells, or PD-L1 on tumor cells, to restore T-cells’ anti-tumor activity [9].