The biological basis for the BCL2 co-dependence in t(11;14) myeloma remains a mystery, however gene expression profiling of myeloma patient samples did reveal that t(11;14) were composed of two gene expression groups, CD1 and CD2, where CD2 had increased expression of B cell markers such as CD20, PAX5, and VPREB3, suggesting a possible connection with B cells and BCL2 dependence. Here, PAX5 is linked to plasma cell myeloma.