GSK3B and B-cell chronic lymphocytic leukemia: We first inhibited GSK3β activity by culturing CLL cells for 3 h with increasing concentrations of the GSK3β inhibitor SB216763 [42] or DMSO as control (n = 8), before Western blot (WB) analysis of the active NOTCH1 intracellular domain (N1-ICD) and NOTCH1-transmembrane subunit (N1-TM).