Given that inhibition of GSK3β enhances NOTCH1 signaling, which has been shown to promote CLL cell survival [5–7], we performed MTS assay in CLL cells treated with SB216763 for 18 h (n = 8), to assess whether GSK3β directly modulates CLL cell viability. This evidence concerns the gene GSK3B and B-cell chronic lymphocytic leukemia.