Physical barriers stipulated by the tumor stroma, soluble products of impaired cellular metabolism in the tumor, an acidic environment and inhibitory proteins such as PD-L1 can inhibit the recruitment, invasion, activation, and persistence of CAR-T cells in tumor tissue, promoting the recruitment of immunosuppressor cells (Treg, MDSCs, and TAMs) and allowing tumor cells to avoid immune recognition. This evidence concerns the gene CD274 and neoplasm.