Inhibition of furin decreases tumor growth in some preclinical tumor models [28], [29], [30], while other tumor models indicate a more complex contribution of PCs to tumorigenesis [31], [32] Thus, although the dual role of PCs in tumorigenesis has to be further investigated, PCs represent a promising target to decrease or even prevent the activation of cancer-promoting factors [33]. Here, FURIN is linked to cancer.