RNASET2 and ovarian cancer: In keeping with the alarmin hypothesis, overexpression in human ovarian cancer cells of an engineered RNASET2 protein bearing an endoplasmic reticulum retention signal (to prevent protein secretion) largely restored the ability of these cells to form fast-growing tumors in vivo, thus demonstrating the key role of extracellular RNASET2 in tumor suppression (62).