BIRC3 and B-cell chronic lymphocytic leukemia: BIRC3 mutations were generated in a monoallelic or a biallelic fashion either in BIRC3 exon 2 or exon 7, having as a consequence the truncation of the BIR or CARD BIRC3 protein domains, respectively (Fig. 1B, left panel), emulating the type of BIRC3 mutations mainly detected in CLL [12, 16].