MMP9 and breast cancer: In an attempt to ascertain the function of lncRNA ROR in breast cancer, breast cancer MCF-7 cells were transfected with sh-lncRNA ROR and oe-lncRNA ROR, respectively, the results of which indicated that silencing of lncRNA ROR triggered a decrease in the expression of Vimentin, N-cadherin, MMP-2, MMP-9, Ki67, PCNA and Bcl-2, while elevated levels of E-cadherin, Bax and Cleaved caspase-3, indicating inhibited cell proliferation and invasion and promoted apoptosis in breast cancer.