Many studies have found that tumor tissue and biopsy samples display elevated expression of CMG components relative to non-tumor tissue.[1,2] Such elevated expression of CMG components in tumor tissue is often referred to as “overexpressed,” providing an argument that CMG helicases (like other overexpressed cell cycle regulating proteins) might be drivers of cancer growth and thus suitable for the development of drugs that can inhibit CMG function for cancer treatment (reviewed in ref. [1]). This evidence concerns the gene CASK and cancer.