Malignant plasma cells express lower levels of tumor antigens and human leukocyte antigen (HLA) molecules [21,22], as well as higher levels of programmed cell death ligand 1 (PD-L1), which have been linked to defects in the antigen-presenting capacity of dendritic cells and a state of immune tolerance, respectively [23,24]. The gene discussed is CD274; the disease is neoplasm.