STAT3 and posterior cortical atrophy: Moreover, as shown in Fig. 5g, h, p-STAT3 and MMP9 protein levels were increased by KLF5 knockdown, while niclosamide treatment suppressed the expression of not only p-STAT3 but also MMP9, suggesting that activation of STAT3/MMP9 is essential for the increased cell invasive ability by KLF5 knockdown in PCa cells.