As extensive literature data showed that in TME, in addition to cancer cells, stromal cells such as the antigen-presenting cells (APCs) MDSC, DCs, and macrophages, are the main sources of PD-L1 [17–20], we further investigated where in the TME, the PD-L1 expression level was affected following β3-AR blockade. The gene discussed is CD274; the disease is cancer.