CXCL8 and brain neoplasm: In brain tumor patients the 20S proteasome ChT-L activity showed a positive correlation with only IL-8 concentration (r = 0.508; p = 0.0031) (Fig 5); we did not observe a relationship between the 20S proteasome ChT-L activity and CCL2, NF-κB1 as well as the NF-κB2 concentration (p>0.05).