TNFSF13B and acute lymphoblastic leukemia: To demonstrate the functional integrity of BAFF-system receptors in B-ALL cells, we evaluated whether their ligation triggered the activation of NF-κB, MAPK, and PI3K/Akt signaling, which are critical events on survival and proliferation of malignant B-cells.[36], [37], [38] Since BAFF-R was the most frequently expressed receptor (Figure 1), the ensuing studies were performed using BAFF.