This set of results provide evidence that NRARP, aside from having a suppressive role in T-ALL by inhibiting Notch signaling (e.g., in CEM and DND4.1 cells) can also promote T-ALL proliferation by potentiating Wnt signaling through LEF1 (e.g., in Loucy and TALL-1). The gene discussed is TNFSF13B; the disease is acute lymphoblastic leukemia.