PRC1 and neoplasm: Through the combination with polycomb repressive complex 1 (PRC1), HOTAIR can achieve the trimethylation of the 27th lysine of histone H3 and regulate Wnt/β link protein, phosphatidylinositol 3-kinase and other signaling pathways through gene silencing to promote tumor invasion and metastasis, avoid growth inhibition and resist cell apoptosis18.