To validate these findings, CT26 cells were stained with fluorochrome-labeled antibodies specific for PD-L1 and CTLA-4, followed by a flow cytometry analysis, which confirmed the poor expression of PD-L1 (2.24%) but significant expression of B7-1 (30.5%) on CT26 tumor cells (Figure 8A). This evidence concerns the gene CTLA4 and neoplasm.