CXCL8 and cancer: As most cytokines/chemokines regulated by DKK1 in cancer cells (including IL1B and CXCL8) are established NFkB-target genes and SOCS-molecules mediate ubiquitin-dependent degradation of various proteins including the canonical NFkB subunit RelA (=p65)25–27, we next quantified protein levels of the latter by subcellular fractionation and immunoblotting.