Moreover, 10 of the differentially expressed protein coding genes (MMP1, MMP9, COL1A2, GREM1, POSTN, FMOD, THSB, DCN, VCAN, CTSK, and IVL) revealed by microarray analysis of tumor cells cultured in spheroids were selected for verification by qRT-PCR. The gene discussed is MMP9; the disease is neoplasm.