CD274 and neoplasm: The immune microenvironment of cold tumors has fewer immune cells such as T cells and NK cells due to the activation of immunosuppressive pathways of immune checkpoints (ICs) such as PD‐1/PD‐L1 and CTLA‐4, and more immunosuppressive factors like interleukin 10 (IL‐10) and transforming growth factor beta, thus inhibiting the proliferation and activation of immune cells, while IC molecules such as PD‐L1 on the surface of tumor cells also inhibit the activation of immune cells.