In our assays, microbial Ags not only directly increased the expression of MHC-II, CD40 and CD80 and changing tumor biology, but the direct presentation of microbial Ags by myeloma cells to Th2 cells could directly stimulate myeloma clonogenicity, much different from the conclusions in prior studies [19–21]. The gene discussed is CD40; the disease is plasma cell myeloma.