Because CLIC4 levels in serum from patients with benign tumors27 and in benign tumor secretomes (Fig. 5d) are typically lower than in patients with malignant tumors, we hypothesize that the intracellular location of CLIC4 might be an important factor in determining the extent to which the protein is shed into the interstitial space and subsequently into the blood. This evidence concerns the gene CLIC4 and benign neoplasm.