 "CD38, CD138, IR4/MUM1, XBP1, IL21R", and/or "PRDM1").The abnormalities in gene structures and expressions reported in the Pathophysiology section, particularly rearrangement and/or over expression of the "MYC" proto-oncogene, may also be apparent in these cells.The presence of HIV/AIDS or other causes of immuno-incompetence (see previous section), a history of having a low-grade lymphoma, and/or the presence of EVB+ plasmablasts in the disease's lesions would support the diagnosis of PBL.