Furthermore, transfection of CLL cells with STAT3-shRNA, but not with the empty lentiviral vector, significantly downregulated the expression levels of STAT3, GLI1 and GLI1-target genes that are not STAT3-target genes, and of STAT3 and GLI1 protein levels (Figure 2C). Here, GLI1 is linked to B-cell chronic lymphocytic leukemia.