XIST and cancer: In the context of gastrointestinal tumors, XIST was also found to be overexpressed in gastric cancer tissues and associated with an aggressive tumor phenotype and adverse prognosis; XIST’s oncogenic power was demonstrated both in vitro and in vivo and at least partly attributed to the sponging activity of miR-101, resulting in the de-repression of the Polycomb group protein enhancer of zeste homolog 2 (EZH2) and promotion of cancer progression and metastasis [68].