CTSK and B-cell chronic lymphocytic leukemia: Among the genes that were upregulated in MSCs upon CLL cell co-culture, we identified coding genes for several proteases, such as matrix metalloproteinase 1 (MMP1) or cathepsin k (CTSK), or inflammatory factors, such as interleukin 1 β (IL1B) or C-X-C motif chemokine ligand 8 (CXCL8).