MALAT1 and metastatic carcinoma: MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is a nuclear-enriched lncRNA that was originally discovered in metastatic carcinoma cells, and subsequently found to be markedly upregulated in many types of cancer (32), and thus it has been investigated as a prognostic biomarker and potential therapeutic target for metastatic cancers (5,32–38).