Quite the opposite, there is quantitative evidence that CMG protein components are expressed at very similar levels (in terms of total protein molecules) in individual proliferating non-tumor and tumor cells.[3] A likely explanation for these discrepancies is that tumor tissue is in a heightened proliferative state that renders the CMG helicases noticeably elevated in immunohistochemical staining assays relative to that seen in normal, non-tumor tissue with a lower proliferative index (or non-proliferating tissue). The gene discussed is CASK; the disease is neoplasm.