XIST and neoplasm: Various therapeutic strategies can be based on boosting the expression level of a “beneficial” miRNA or inhibiting a harmful one; of note, different studies demonstrated that knock-down of a lncRNA such as XIST [68,69,75,76,77,78,79,83,84,85,86], or FTX [176] and JPX [188,189], exerts tumor-suppressive functions in vitro and in vivo, validating new therapeutic targets.