CREB expression and CREB_S133 phosphorylation was found to be above that of normal CD34+ cells in 17.1% and 5.0% of the ALL patient samples, respectively, while 25.7% (CREB) and 66.4% (phospho-CREB_S133) of the primary ALL samples showed expression below that of normal bone marrow CD34+ cells (Figure 3A and 3B, Supplementary Table 5A). Here, CREB1 is linked to acute lymphoblastic leukemia.