Expression of the large and heavily glycosylated MUC16 mucin has previously been shown to interfere with the synapse formation between ovarian cancer cells and NK cells [24]; and the rat homologue of MUC4, the sialomucin complex, has been shown to shield cancer cells from lymphokine activated killer cells, thereby increasing their metastatic potential [52], [53]. Here, MUC5AC is linked to cancer.