Expression of (a) TXS, (b) MMP-9, and (c) PAI-1 in U937 cells. U937 cells were treated with SWE, TPA, or scu for 12 h, and gene expression was analyzed by real-time PCR performed using a specific primer described in Section 2. Values are expressed as mean ± SD of four replicates. Different letters (a, b, and c) represent statistically significant difference of means compared to the values of controls and compared between groups ().