PVT1 and breast cancer: Recently, several studies have shown that plasmacytoma variant translocation 1 (PVT1) is overexpressed in human tumors, including non-small cell lung cancer (NSCLC) [37], small cell lung cancer (SCLC) [38], gastric cancer [39] and breast cancer [40], where it functions as an oncogene and regulates cancer cell metastasis.