Giannoni et al. [33] demonstrated that co-culture of bone-marrow stromal cells with CLL cells halts this process: key markers of mature osteoblasts (RUNX2, osteocalcin) fall sharply, and inhibitors of osteoblastogenesis (DKK-1, osteopontin) rise. This evidence concerns the gene DKK1 and B-cell chronic lymphocytic leukemia.