XIST and neoplasm: XIST may have tumour suppressor functions in cervical, breast, hepatocellular, prostate and osteosarcoma cancers29, 30, 31, 32, 33, 34 and may act as a tumour promoter in pancreatic, bladder, colon, thyroid, gastric and glioblastoma cancers.35, 36, 37, 38, 39, 40, 41