TUG1 and neoplasm: lncRNAs with a demonstrated ability to regulate tumor metastasis (e.g., lincIRX5 and lincFOXF1) and lncRNAs with unclear functions (e.g., lincMTX2 and lincTNS1) might have the potential to regulate CRC liver metastasis in a manner similar to that of TUG1 and MALAT1.