They also explored the molecular mechanisms underlying the function of MALAT1 in osteosarcoma and observed that MALAT1 inhibited tumor growth and metastasis via the PI3K/AKT signaling pathway, as the expression levels of proliferating cell nuclear antigen, matrix metallopeptidase 9 (MMP-9), phosphorylated PI3Kp85α, and Akt were significantly decreased in MALAT1-knockdown cells.94 Cai et al.95 observed similar results in MALAT1 siRNA-treated osteosarcoma cells. The gene discussed is MMP9; the disease is osteosarcoma.