PD-L1 can provide inhibitory co-stimulatory signals to T cells after binding to the receptor PD-1, generating a negative regulatory effect, thus inhibiting the activation and proliferation of T cells, and inducing apoptosis of T cells, which mediates the occurrence of immune escape in tumor cells, avoiding the body’s immune surveillance and the development of immune response in tumor cells (5). Here, CD274 is linked to neoplasm.