KCNQ1OT1 and neoplasm: In this work, we demonstrated that a large subgroup of WTs showed methylation imprinting abnormalities at multiple loci, including H19, KCNQ1OT1, PLAGL1, GNAS, MEST, GRB10 and MEG3. We observed that the WT cases with epimutations at more than one imprinted chromosome region correspond to more advanced tumor stages and have more frequent metastases with respect to the cases with single-locus defects or normal imprinting, suggesting that multiple imprinting defects arise mostly during the late stages of tumorigenesis.