MMP9 and neoplasm: Because RAC signaling plays a role in tumor invasion, we hypothesized that a number of markers of EMT and/or invasion would be altered upon Elmo1 knockdown, and indeed observed reduction in the mRNA expression of Snail, αSma, Vimentin, Zeb2 and Mmp9 in CD34+ cells isolated from Tgfbr2 cKO tumors infected with both Elmo1 shRNA constructs #1 and #2 compared to those infected with SH02 control (Figure 9B).