CTLA4 and neoplasm: Unexpectedly, in parallel to the increased expression of PD-1 receptor and its ligand, we also found a significant increase of CTLA-4 expression on the indicated tumor cells after treatment with the antagonists Nivolumab and 10_12, whereas again an opposite effect (decrease in the expression of CTLA-4) was observed under treatments with PD-1/PD-L1 agonists (see Figure 3B).