In light of the previous evidence that MCC specifically targets and negatively regulates the oncogenic NF-κB and β-catenin pathways in CRCs and hepatocellular carcinoma [20,27,32,36], we determined the effects of MCC knockdown on the levels of these two pathways in human MM cells, including IκBα, IκBβ, RelA, phospho-β-catenin and β-catenin [20,27,32,36]. Here, RELA is linked to Miyoshi myopathy.