Quantitative RT-PCR analysis of CTGF, MMP2, MMP-3, and miR-519d performed in osteosarcoma and normal samples, showed negative correlation between CTGF and miR-519d; positive correlation between CTGF and MMP-2, CTGF and MMP-3 (Fig. 6B-D). The gene discussed is CCN2; the disease is osteosarcoma.