TGFB1 and non-small cell lung carcinoma: To further elucidate the effect of lnc-MMP2-2 in NSCLC brain metastasis in vivo, a brain metastasis mouse model was established by implanting stably transfected A549 cells with control or shlnc-MMP2-2 lentivirus treated with or without TGF-β1.