CD274 and plasma cell myeloma: This upregulation contributes to the immunosuppressive nature of the TME and can influence the efficacy of immunotherapies targeting the PD‐1/PD‐L1 axis.[36] Our work discovered that chemotherapy upregulates the expression of PD‐L1 in myeloma cells, but it is still unclear whether it can regulate the PD‐L1 expression on T cells, macrophages, DCs, B cells, or NK cells.