MMP9 and renal cell carcinoma: Furthermore, H&E staining of those metastatic foci confirmed that those are indeed RCC cells, including those in diaphragm and hepatic hilar region (Figure 6D), and IHC staining for AR, HIF2α, VEGF, MMP9 and CCND1 were also in agreement with in vitro results showing AR-suppressed miR-145 is a key player to suppress RCC progression via modulation of HIF2α/VEGF/MMP9/CCND1 signals (Figure 6E).