IL6 and acute lymphoblastic leukemia: Finally, the absence of negative regulation exerted by the NF-κB1/p50 subunit on the IL-6 promoter, as observed in DP T-ALL cells from N3tg/p50−/− double mutant mice (Figure 4C, lower panel, #3), induces a further increase in the p65 binding to the IL-6 promoter.