NFKB1 and B-cell chronic lymphocytic leukemia: Indeed, deletion (78%) or mutation (8%) of BIRC3 is common among 11q22.3-q23.1 (11q-) CLL patients and is associated with less favorable outcomes [55], possibly because inactivation of the BIRC3 gene leads to the constitutive activation of the non-canonical NF-kB pathway [56].