IRF4 and mantle cell lymphoma: Consistent with our pooled CRISPR screening results, transduction of the green fluorescent protein (GFP) reporter coexpressing sgRNA constructs targeting EBF1, FOXO1, IRF4, or PAX5 severely impaired the growth of MCL cell lines JEKO1 (Figure 1D) and CCMCL1 (Supplemental Figure 1D).