Infection of the cells with the pLVX-mCherry vector did not affect the efficiency of the shRNA, as we observed a similar reduction in Elmo1 mRNA compared to CD34+ cells isolated from SH02 tumors that did not express the mCherry (50% reduction for construct #1 and 60% reduction for construct #2 (Figure 9—figure supplement 1C). Here, CD34 is linked to infection.